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Chapter XXXVII

Books and Documents > Medical Department of the U.S. Army in the World War, Volume III, Finance & Supply

CHAPTER XXXVII

X-RAY EQUIPMENT AND SUPPLIES

The X-ray apparatus in the possession of the Medical Department when we entered the World War consisted of the stationary apparatus at general hospitals and at the larger military posts. In addition there were a few portable sets which had been developed during the years immediately preceeding 1917. This portable outfit consisted of a motor generator and a high-tension transformer. The motor generator was composed of a gas engine of the marine type, a direct-connected alternating-current generator, and a rectifying disk mounted on the shaft of the motor. These had served a good purpose on the Mexican border and at Vera Cruz, but were cumbersome and unreliable for the work of a great war.1

The problems presented to the Medical Department when we entered the World War, with regard to X-ray equipment, were to provide stationary X-ray plants in sufficient numbers for the fixed hospitals in the United States and overseas, and to devise and secure the manufacture of a practicable portable apparatus.1 In this connection, the American Roentgen Ray Society was of material assistance to the Medical Department.

STATIONARY APPARATUS

In the latter part of 1916 the American Roentgen Ray Society appointed a committee on preparedness, the function of which was to consider ways and means whereby the members of the society could render the most effectual service to the Government in the event of the entry of the United States into the war. This committee gave considerable attention to matters of X-ray equipment. In the early part of 1917 a special committee was appointed by the society to standardize X-ray apparatus and equipment. Because of the extremely technical nature of the X-ray apparatus it was decided that it would be impracticable and unnecessary to have all machines purchased identical in all respects. Individual processes and designs could be continued so long as the machines produced came clearly within the particular general requirements. Specifications for X-ray machines were drawn up by the committee with that object in view; performance tests were given more consideration than physical appearance and design. It was the conclusion of the committee that five types of apparatus, made by the five principal manufacturers, would come within the specifications 2

The committee compiled a list of all the apparatus and accessory articles needed for any kind of work likely to be required in the large military hospitals in the United States or in the base hospitals overseas. Specifications were prepared for the essential parts of the equipment, such as X-ray machine,


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roentgenscopic table, tube racks, tube stands, and vertical roentgenscopes. This standard list was furnished the Surgeon General May 1, 1917, and served as the basis of the early procurement.3 The list as originally compiled was modified from time to time as experience suggested, but these modifications were only in minor details. The list was revised and with amendments and additions published as Part IV, “X-ray apparatus and supplies,” List of Staple Medical and Surgical Supplies, Council of National Defense.

With this standard list of equipment, the problem presented was the procurement of X-ray machines in sufficient numbers to meet the immediate requirements in the United States. These machines were secured by giving orders, in as nearly equal numbers as possible, to five of the largest manufacturers of such apparatus.4 These manufacturers were selected because the machines manufactured by them were known to be satisfactory in all the civil hospitals. They had also been tested out by the Medical Department of the Army. It was impossible to provide a single type or make of X-ray machine because of the inability of any one manufacturer to furnish the machines rapidly enough. It was found that nearly all the machines to be furnished in the United States could be built for alternating current. The few places where only direct current was furnished were supplied with comparatively little delay with direct-current machines, a few of which were procured.1

The apparatus installed in the various large military hospitals in the United States proved very satisfactory. Accordingly, decision was reached to provide the large hospitals to be established overseas with the same type of equipment. Some disappointment was experienced with the X-ray machines sent overseas because of insufficient information concerning current conditions in France. It was very difficult at the beginning of the war to secure rotary converters in large numbers, and the machines to be furnished rapidly were necessarily constructed for alternating current. It was deemed advisable to send alternating-current machines in sufficient numbers for the hospitals then contemplated in France, and to convert such of these as were necessary into direct-current machines by providing rotary converters.1 Some difficulty was experienced in securing these rotary converters, which resulted in delay in providing X-ray apparatus for places where there was only a direct-current supply. Even in those places the emergency was met by providing another type of equipment known as the bedside apparatus.1

PORTABLE OUTFITS

There were very few hospitals in the United States which could not be supplied readily with electric current from some outside plant. It was anticipated, however, that many hospitals in France would be so placed that no electric current of any sort would be available. If such hospitals were to be provided with an X-ray outfit it must be able to generate its own current. This anticipated need for such equipment received early attention. A satisfactory portable outfit was developed through the combined efforts of the engineers of the General Electric Co., of Schenectady, N. Y.; the Domestic Engineering Co., of Dayton, Ohio; and the Victor X-ray Corporation of Chicago. Specifications for the outfit were submitted to the Surgeon General


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June 13, 1917. This outfit was devised largely by Dr. W. D. Coolidge and his assistant, Mr. Moore, in the research laboratory of the General Electric Co. It consisted essentially of a direct-connected gas-engine generator, a step-up transformer, a filament current transformer, a filament current control, a small booster, and the necessary milliammeters, voltmeters, and operating switches. 1

FIG. 37.- Portable X-ray outfit, model of 1917. Table top removed

The generating apparatus consisted of a Delco-light engine manufactured by the Domestic Engineering Co. This engine was directly connected to a dynamo of 1 kilowatt capacity delivering a direct current at 32 volts. It was modified by changing the armature and field windings and by adding a pair of slip rings so as to furnish an alternating current. A throttle governor was provided to regulate the voltage. This governor consisted of a solenoid mounted above the carburetor, the movable core of the solenoid being connected to the butterfly valve of the throttle. The solenoid was operated by direct current taken from the commutator on the generator.1

The X-ray transformer was an oil-insulated, closed-core type of transformer, the middle point of whose secondary winding was grounded and connected to the milliammeter. The filament current transformer was also oil insulated. The remaining electrical parts of the outfit consisted of a filament current control, a small “booster” to prevent current drop when the load was thrown on an operating switch, a milliammeter, a voltmeter, and the X-ray tube. The latter was a tube designed by Doctor Coolidge especially for this outfit and was a modification of the original Coolidge tube. It was called a radiator tube and


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was so constructed that it rectified its own current. It thereby rendered complicated and cumbersome rectifying devices unnecessary.1

The electrical parts of the outfit were mounted in a solidly constructed box called the instrument box. This box was connected to the generator set by a 50-foot cable. The instrument box, when in use, was placed at the end of the X-ray table, and the engine at any convenient place within 50 feet.1

The portable outfit was used in France in many evacuation hospitals, mobile hospitals, and even in some field hospitals. It was a simple, highly efficient, and readily transportable outfit. Its total weight was less than 1,000 pounds. The outfit was remodeled and greatly improved during 1919. Practically all the defects noted during the war were eliminated.1

FIG. 38. - Standard bedside X-ray outfit

BEDSIDE UNIT

While the development of the portable outfit generating its own current was in progress another portable type of apparatus which did not have its own generating plant was devised by Prof. J. S. Shearer, of Cornell University. This apparatus was complete in one small cabinet, to which was attached a tube stand carrying a very flexible tube holder. The X-ray transformer was placed inside this cabinet. The special point in the construction of this transformer was that the Coolidge filament transformer was an integral part of the


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main X-ray transformer. The necessity for an extra transformer for the filament current of the Coolidge tube was thereby avoided. The radiator type of Coolidge tube was used by this apparatus also. This apparatus was called a bedside unit.1

The bedside unit filled a place of great usefulness during the war. It could be operated on either direct or alternating current, and its capacity was limited so that it could be attached directly to any electric lighting socket. This made it very portable and enabled it to be used at the bedside in the wards as its name suggests. This was done in thousands of cases of chest complications accompanying influenza during the epidemic of 1918, and in the case of many fractures that could not be moved to the X-ray room. Professor Shearer was able later, in France, to make a simple modification that made it possible to operate the bedside unit from the current supplied by the Delco engine of the portable outfit.1

MOBILE OUTFITS

A highly satisfactory portable outfit had been developed, as already noted, but it had to be loaded into some kind of a truck to be moved from one place to another. It seemed desirable to have special transportation for a number of these portable outfits so that they could be sent quickly to mobile or evacuation hospitals or other points where wounded were being brought in unusual numbers. This was accomplished by a simple modification of the standard United States Army ambulance so that the entire outfit, including the standard Army portable X-ray table, could he transported safely and put into operation in a few minutes.1 The gas-engine generator was mounted on a heavy wooden base of 2-inch material and placed inside the ambulance body just behind the driver’s seat. This base was fastened by screws to a frame secured to the side walls and floor of the ambulance body. The instrument box, bedside unit, and other equipment were packed in the space between the generator and the rear end of the body. The table top was suspended on the outside of the body flat against the side and protected from the rain by a waterproof canvas curtain which rolled down over the outside of the table top.

Only 17 of these mobile outfits actually reached France, and none of them could be placed in service prior to the armistice. Five of them accompanied the Third Army into Germany, where their usefulness was thoroughly demonstrated.

LIST OF UNIT EQUIPMENT

Since the hospitals in which the X-ray apparatus was installed varied in size from 25 beds to more than 1,000 beds, it became necessary to select the apparatus and provide a list of accessory articles for hospitals of varying size. It was decided to furnish the standard bedside X-ray unit as suitable equipment to hospitals of less than 75 beds and to provide the larger hospitals with the standard X-ray apparatus of interrupterless type and with supplies and accessories according to the size of the hospital. Accordingly, lists of equipment were prepared.5 These lists, in order of sequence, follow.


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SPECIFICATIONS B, FOR STATIONARY X-RAY MACHINE (INTERRUPTERLESS TYPE)

Each machine to consist of the articles enumerated below.
Cabinet. - A cabinet made of high-grade hardwood free of knots or blemish; all glass parts best French plate not less than three-sixteenths inch thick.
Transformer. - A high-tension transformer, having a normal rating of at least 10 kilowatts, transformer winding to be so proportioned that it will deliver at its secondary terminals an alternating current of at least 100,000 volts potential in actual service. It must stand a continuous run of two hours at 60,000 volts, delivering 5 milliamperes to the tube and backing up an 8-inch spark, and be capable of delivering 50 milliamperes to the tube backing up a 6-inch spark.

Rectifier
. - A rotary high-tension rectifying or commutating device accurately balanced, directly connected with the shaft of the rotary converter or synchronous motor set, adjusted to revolve near or in contact with suitable terminals by means of which the high-tension alternating current from the transformer is changed into a high-tension pulsating unidirectional one through the tube circuit; and in case a disk type of rectifying device is employed, the disk must be cut out between the conducting segments so as to provide an ample air gap, or the metal collecting segments must be set out from the edge of the disk.

Switchboard. - A substantial switchboard of good insulating materials, on which are securely mounted the necessary switches for properly operating the outfit; each outfit to be provided with a polarity indicator.
Motor. - A satisfactory synchronous motor, of suitable rating, operating on an alternating current of the phase and potential noted in the circular of advertisement, same to be provided with all the necessary connections for proper operation.

Control
. - A controlling rheostat for primary of the high-tension transformer, to be well ventilated and so constructed and mounted as to permit of fine graduation of current flow and to operate continuously for fluoroscopy or treatment without overheating. In addition to the rheostat, an auto-transformer control will be furnished.

Milliammeter. - A milliammeter, reading accurately and with an 8-inch double scale, with shunt reading 0-10 and 0-100 milliamperes securely mounted on the machine and conveniently placed for observation.

Mountings. - Switch board, transformer, rheostats, motors, time switch, connections, etc., to be mounted on the cabinet, or detached, as specified in the circular of advertisement. A separate rheostat for the primary will be allowed if satisfactory in appearance and size.

Terminals. - Each machine to be provided with substantial terminal posts mounted on the cabinet and automatic conductor cord reel (8-foot cords) for directly connecting with an X-ray table to be attached to each post. The two main terminals to have an adjustable parallel spark gap of riot less than 10 inches, the third terminal to be provided with, a suitable device for regulating the vacuum of the tube. All spark gap and regulating devices to be so regulated and designed that they can be conveniently and easily manipulated from the switchboard end of the machine.

Fluoroscopy. - Machine to deliver a satisfactory current for making fluoroscopic observations.

Connections. - Such fuses and internal connections as may be required to operate the outfit: two 10-foot lengths of best quality No. 2 flexible conductor cord with suitable lugs, etc., on its ends, for connecting the machine with the terminals of the main feed wires.
Each machine to be complete, with all necessary connections, to be practically noiseless in operation, and to run without noticeable vibration.

Each outfit to be well constructed mechanically in every detail; materials to be best quality; workmanship and finish to he first class in every respect. Apparatus to be so constructed that it can be set up and all electrical connections made without the aid of an expert and all parts of the outfit to be readily accessible for inspection.

All parts of the apparatus, mechanical and electrical, to be guaranteed for two and one-half years from the date of delivery, during which, tune breakdowns resulting from defects in the apparatus will be repaired by the contractor without expense to the purchaser.


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Detailed blue prints and specifications for the apparatus, showing clearly the internal construction of the various parts, to accompany each bid. Such blue prints and specifications as are not required will be returned to the bidder. The acceptance of each machine shall be contingent upon actual testing out of machine at place of delivery specified in contract of purchase.

SPECIFICATION B, PORTABLE AND BASE HOSPITAL X-RAY TABLE

Table, X-ray, for portable apparatus, consisting of pair of cast aluminum end frames; slotted to receive four tubing members each 6 feet long, each end of these four members (which are interchangeable) to be provided with a screw and handle which locks them rigidly in place in the slots, providing a light, strong, and rigid frame upon which the regulation litter or a special top may be laid. The top of the table will have the following specifications:

Dimensions.- Length over all, 83 inches; width over all, 26 inches; rails, 2 by 2 inches.

Material.- Rails and handles of straight-grained sound wood, free from knots. Handles round, straight-grained rod of suitable size. Tops of “Continental Bakelite,” approximately one-tenth inch thick and of dimensions as ordered by the builder.

Finish. - Woodwork to be finished in as nearly waterproof manlier as possible. No finish on Bakelite.

Construction.- Rectangular frame 6 feet 4 inches by 26 inches outside; well constructed. Each side rail to have a groove as shown by sample submitted. Rail slit to take Bakelite top, with glue and dowel pin, as shown in model and sample submitted. Top to be as tense as material will permit.

Rail Frame. -To allow shift of patient; rectangular frame of straight grained 2 by 2-inch wood. One side rail with raised ridge to take groove of top. Crosspieces to be attached under side rails with screws and angle iron, to allow these pieces to fit between metal frames of standard table 6 feet 2 inches inside. Side rails to be 6 feet 8 incises long.

A roller-supported carriage is constructed to travel on tops of the upper side members and fitted with roller bearings. This carriage consists of two side members of square cross section and two transverse members of round cross section. Traveling on the round cross members and underslung there is a tube box supported by spool rollers with roller bearings, box to be covered with lead having weight of 4 pounds to a square foot. The opening in the middle of the top of the box will be provided with diaphragms, the shutters of which may be moved independently arid give a diamond-shaped opening or slit parallel to long axis of the table at will. The box must be so constructed as to carry conveniently and safely the special type of Coolidge tube described below and provide for free access of air to the radiator. Stops should be provided on the tube-box carrier, which with sliding rings provided with milled head screws will permit of a tube shift of (a)10 cm., (b)15 cm., (c) any desired shift to be measured by calipers. The tube mounting must be provided to pass through the end of the box and with attachments for Coolidge filament and operating wires from the reels. A simple catch is provided to fasten the tube carrier in place. The radiator must be protected from injury by covering the ventilating openings with wire netting. Convenient brakes are to be provided to fix the tube carriage in its longitudinal and lateral runs. A string-operated switch, 10 amperes, 250 volts, is to be provided, having special clamp to attach same to table and with eyelets on the carriage to keep string in place. The switch must open or close two circuits simultaneously. Flexible 4-wire cable is attached to this switch, having at the other end plug connection fitting sockets in the instrument box.

Fluoroscope, for portable apparatus; dimensions 10 by 10 inches. The carrier to have the following features:
1. It must run easily on suitable bearings on two side rails of the table.
2. It must be readily locked in any desired position independent of tube box.
3. Provision should also he made to lock the carrier to the tube box.
4. The arm carrying the screen should be capable of rotation about a vertical axis.


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5. A metal frame holding the screen should be fastened to this arm at one corner of the frame so as to allow rotation of the screen about a vertical axis passing through the corner.
6. The screen, with its frame and lead glass, should be easily removable from the holder to permit its use separately when desired.
7. The screen will be pierced in its exact center by circular hole, 3 mm. in diameter and lined with aluminum.

The specifications for the base hospital table are identical with those above except as follows:
1. The tube box shall take the regular type of tube instead of the radiator type. The mounting on the carrier to be interchangeable with the placing of the stretcher top or its movement parallel to the length of the table.
2. Suitable high-tension insulated leads are to be attached by clamps to the ends of the table so arranged as not to interfere in any way with the placing of the stretcher top or its movenment parallel to the length of the table.

SPECIFICATION C, FOR TUBE STAND

The tube stand shall be of the general type originated by the Kelley-Koett Co., so constructed and counterbalanced that the tube carriage will move smoothly and easily and remain in any position without adjustment of screws or other contrivances. The stand must be of strong and rigid construction so that there is no noticeable vibration when in use, nor perceptible movement of the tube carriage when being used for compression of the abdomen while the patient breathes. Arrangement must be made for shifting the tube both laterally and in the directions of the length of the table and for tilting it for stereoscopic work.

Stand must be provided with a lead glass bowl equal in capacity to one-sixteenth inch lead. The base must be of a size and weight to render stand secure against overturning and provided with large easily acting and tracking castors with at least one-half inch, trail. Highest part of base must not exceed 6 inches from floor. Stand must be provided with slot for diaphragms and filters and with two cones, one 5-inch and one 6-inch diameter, and a set of aluminum filters of 1, 2, 3, and 4 mm.

PORTABLE X-RAY OUTFIT APPARATUS

Booster, for portable apparatus, to take care of drop in voltage, in filament circuit when full lead is thrown on the gas-electric set; shall be of such designs that with its primary in series with the supply voltage and its secondary in series with the primary of the filament transformer it will compensate for the drop in voltage to such an extent that the filament current will not vary over 0.2 ampere from its original setting; furnished with switch by which booster can be short-circuited.

Gasoline electric set (Delco), for portable apparatus, consisting of a one-cylinder gasoline engine with a built-in generator, with the following modifications: (1) Special armature winding with slip rings so that both alternating and direct current are available, direct current being used for field excitation; (2) special ignition system, rendering use of storage batteries unnecessary; (3) special voltage control by which a solenoid fed by direct current supply controls the carburetor; (4) suitable resistance across alternating-current and direct-current terminals to protect from surges. Capacity, 750 watts. Each machine to be packed in a permanent shipping and carrying case, and to be furnished with onie set of extra brushes and fuses.

Filament control, inductive type, capable of giving a variation over a range from 4 to 5 amperes in the filament circuit.

Rheostat for solenoid control of engine speed, to have a resistance of approximately 2,000 ohms and to be capable of carrying continuously not less than 0.25 ampere, to be substantially constructed, thse wires shellacked or enameled in position and with metal bands clamping the windings at end of cylinder.

Transformer, for portable apparatus, closed-core type, both terminals developed, oil insulation, provided with an oil-tight top. When excited by the gas-electric set described


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above and using only one-half of the sine wave, it shall be capable of delivering to the X-ray tube 10 milliamperes, with a useful voltage corresponding to a back-up spark of 5 inches between points; this useful voltage to be determined by connecting a kenotron in series with the X-ray tube and measuring the potential drop across the tube by means of a point gap in parallel with the tube. The higher inverse voltage resulting from the use of only one-half of the wave shall be measured by means of a point gap in parallel with both the X-ray tube and kenotron and shall not exceed useful voltage by 3 inches.

Transformer, Coolidge filament-lighting, oil insulated, with an oil-tight cover; primary and secondary windings to be insulated from each other for a voltage not less than that corresponding to a back-up spark of 8 incises measured between points. With double cord reel for connecting the cathode of the X-ray tube arid the transformer; Victor Electric Corporation’s standard transformer for 110 volts, 60 cycle, or equivalent.

PORTABLE X-RAY TABLE TOP

Dimensions, - Length over all, 83 inches; widths over all, 26 inches; rails, 2 by 2 inches.

Material
. - Rails and handles of straight-grained sound wood free from knots. Handles round, straight-grained rods of suitable size. Tops of "Continental Bakelite,” approximately one-tenth inch thick and of dimensions as ordered by the builder.

Finish. - Woodwork to he finished in as nearly waterproof manner as possible. No finish on Bakelite.

Construction. - Rectangular frame, 6 feet 4 inches by 26 inches outside; well constructed. Each side rail to have a groove as shown by sample submitted. Rail slit to take Bakelite top with glue and dowel pin, as shown in model and sample submitted. Top to be as tense as material will permit.

Rail frame. - To allow shift of patients. Rectangular frame of straight-grained 2 by 2 inch wood. One side rail with raised ridge to take groove of top. Cross pieces to he attached under side rails with screws and angle iron. To allow these pieces to fit between metal frames of standard table 6 feet 2 inches inside. Side rails to be 6 feet 8 inches long.

A roller-supported carriage is constructed to travel on tops of the upper side members and fitted with roller bearings. This carriage consists of two side members of square cross sections an two transverse members of round cross section. Traveling on the round cross members and underslung there from is a tube box supported by spool rollers with roller hearings, box to be covered with lead having weight of 4 pounds to square foot. The opening in the middle of the top of the box will be provided with diaphragms, the shutters of which may be moved independently and give a diamond-shaped opening or slit parallel to long axis of the table at will. The box must be so constructed as to carry conveniently and safely the special type of Coolidge tube described below, and provide for free access of air to the radiator. Stops should he provided on tue tube-box carrier, which, with, sliding rings, provided with milled-head screws, will permit of a tube shift of (a)10 cm.; (b)15 cm.; (c)any desired shift, to be measured by calipers. The tube mounting must be provided to pass through the end of the box and with attachments for Coolidge filament and operating wires from the reels. A simple catch is provided to fasten the tube carrier in place. The radiator must he protected from injury by covering the ventilating openings with wire netting. Convenient brakes are to be provided to fix the tube carriage in its longitudinal and lateral runs. A string-operated switch, 10 ampere, 250 volts, is to be provided, having special clamp to attach same to table and with eyelets on the carriage to keep string in place. The switch must open or close two circuits simultaneously. Flexible four-wire cable is attached to this switch having at the outer end plug connection fitting sockets in the instrument box.

Fluoroscope, for portable apparatus; dimensions, 10 by 10 inches; the carrier to have the following features:
1. It must run easily on suitable bearings on two side rails of the table.
2. It must be readily locked ins any desired positions independent of tube box.
3. Provision should also be made to lock the carrier to the tube box.
4. The arm carrying the screen should be capable of rotations about a vertical axis.


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5. A metal frame holding the screen should be fastened to this arm at one corner of the frame so as to allow rotation of the screen about a vertical axis passing through the corner.
6. The screen, with its frame and lead glass, should be easily removable from the holder to permit its use separately when desired.
7. The screen will be pierced in its exact center by circular hole, 3 mm. in diameter, and lined with aluminum.

Tube, special, Coolidge air-cooled type, with radiator type of anode. Tube 3¾ inches in diameter, tungsten target, backed with copper connected to heavy copper rod extending outside tube and connected to air-cooled radiator, capable of rectifying its own current. A shipping and carrying case is to be provided by the company furnishing tube, to be of the general design of that furnished by the General Electric Co.

Voltmeter, alternating current, scale 0-175.

Instrument box, of substantial construction is to be provided in which are permanently the following:
X-ray transformer.
Coolidge filament transformer.
Filament control.
Milliameter C-15 M. B. Weston miniature preferred.
Voltmeter as specified.
Rheostat as specified.
Wiring diagram.
Operating switch.

General design as set up by the Victor Electric Corporation. To be furnished with approved insulators removable for shipment, well-constructed reels, good chest handles or equivalent, split plug connectors, and connecting cable 50 feet long.

SPECIFICATIONS FOR UNITED STATES ARMY BEDSIDE X-RAY UNIT

Cabinet and tube holder. - To be made of best quality polished quartered oak. Door to have piano hinges full length. Base of cabinet, 24 ½ by 15 by 13/8, cabinet 15 incises wide, 19 inches long, and 36 inches high, ¾-inch stock. Polished on all sides. Cabinet to be mounted on rubber-tire wheels 4 inches in diameter. Mounted on the base a nickel-plated tube stand with a hall-bearing arm, ball-bearing head at top, a tube holder made of wood to support the lead-glass holder at each end, and arranged so that the tube can be put into any position. The whole arrangement counterbalanced. The nickel-plated stand to be of 2 ½- inch tubing, 5 feet over all. Lead-glass shields are to be used in connection with the special radiator type of Coolidge X-ray tube, the opening of 2 inches in diameter to be covered with 1 mm. of aluminum, properly mounted on the shield. This lead-glass shield to entirely inclose the X-ray tube, except at the end and the 2-inch opening. This shield to be made of lead glass equivalent to one-sixteenth inch of metallic lead, must be of uniform wall thickness, and pressed instead of blown.

High-tension transformer. - To be of such, a size that it will fit in the upper portion of the cabinet, and is to he mounted in a steel tank with an oil-tight top. To be of the closed-core type and to have the filament current transformer inside of the same tank. Transformer tank to be mounted on a well-braced shelf, rigidly fastened for trans-Atlantic shipment, and leaving sufficient space below shelf for apparatus hereinafter mentioned. Transformers to be designed so that they will deliver a current of 5 milliamperes at a 5-inch useful voltage to the Coolidge tube, and under these conditions operating on the 110-volt, 60-cycle current; the total primary current is not to exceed 5 amperes. Transformers to be designed so that they will operate on any frequency from 25 to 133, without any change in controls or wiring systems. The primary of the transformer to be arranged so that it cams be used with a 110-volt direct-current rotary, a 110-volt alternating current, or a 220-volt direct current, so that its order to change from alternating current to direct current it is simply necessary to throw the switch to the proper side. These positions to be plainly marked with the words “alternating” on one side and direct” on the other.

Cable. - An 8-foot cable to be supplied to connect with the electric service. A 10-foot cable with a foot switch is to be supplied, so arranged that both the filament current and the high-tension current come on at the same instant.


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Milliampere meter, - A  milliampere meter is to be mounted in the top of the cabinet to measure tube current, reading from 0 to 10 milliampere meters. This milliampere meter is to be connected in series in the middle of the secondary and to be grounded to the case.

Reels
. - There is to be a single reel to connect with the positive end of the Coolidge tube, and a 2-wire cable with a lamp socket. to connect with the negative end of the Coolidge tube. All binding posts, tape, or other electrical connections are to be plainly labeled in such a manner as to avoid danger of removal or erasure.

Wiring diagram. - A complete wiring diagram is to be attached to the inside door of the cabinet, protected by a thin sheet of transparent celluloid, and explicit statements of the changes needed in connection when using other than the current herein specified shall be given thereon.

Extension cords. - Twenty-foot lengths with suitable terminals.

X-ray apparatus for base hospital, 500-1,000 beds


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X-ray apparatus for base hospital, 500-1,000 beds - continued

X-ray apparatus for hospitals of 75 to 150 beds


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X-ray apparatus for hospitals of 75 to 150 beds - continued

X-Ray Outfits for hospitals of seventy-five beds or less

Portable outfit complete with accessories


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Portable outfit complete with accessories - continued

Mobile X-ray outfit

PURCHASES

Because of the variation in the types of electric Current generated by the various electrical plants throughout the United States, orders for specific apparatus could not be given until the sites of the camps had been selected and the type of current to be furnished at each camp had been ascertained. Letters were written to the various electric power companies in the vicinity of the camps very shortly after the location of the camps had been furnished the Surgeon General.6 This information was compiled and furnished the officer in charge of the New York medical supply depot. Instructions were issued May 25, 1917, for the purchase of 30 interrupterless apparatus. As soon as it became known that current was available at the hospitals the contracts to the five principal manufacturers of apparatus were let.4 By the time the contracts were let the number of apparatus to be purchased had increased to 37.4 Distribution Within the United States was made quite promptly. Additional machines were furnished as new camps and larger hospitals developed.

Very soon after the military program for the shipment of troops overseas had been made know to the Surgeon General, instructions were issued by the


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finance and supply division of his office for the purchase of 100 complete outfits for hospitals of 1,000 beds for shipment to France.7 In order to provide for various types of current, instructions were issued November 1, 1917, to purchase 50 rotary converters, 7½ kilowatts, shunt wound, 1,800 revolutions per minute, to operate on 220-volt direct current and to produce practically 154 volts, 50 cycle, alternating. Also 50 step-up transformers, primary, tapped for 80, 110, 154 volts; the secondary to deliver 220 volts; all transformers to be oil insulated.8

Following the principle of breaking up the orders, these 100 machines were distributed among four manufacturers.7

In the fall of 1918 arrangements were in progress for the purchase of 100 additional outfits, but before the purchase was consumated hostilities ceased. The total number of these large machines purchased during the World War appears in the tabulation, p.600.

PORTABLE OUTFITS

The first order for portable outfits was for 25 placed during the early summer of 1917. The order for this number was placed with a view of equipping the hospitals at National Guard camps. That plan was shortly changed because it was decided to build the hospitals at those cantonments in pavilion form and to provide them with electric current. This made it possible to utilize the stationary apparatus.9 The portable apparatus were accordingly set aside for shipment to France.

The 25 originally were augmented by 75 in instructions issued from the Surgeon General in the fall of 1917. All of these were intended for shipment overseas.10 Additional purchases of these outfits were made from time to time as required to meet the situation; in all, 393 outfits were purchased.

BEDSIDE UNITS

The first purchase of bedside units was directed in instructions issued from the Surgeon General’s Office September 13, 1917.11 These instructions directed the purchase of 100 such units, including tubes, fluoroscopes, rotary converters, and autotransformers. By that time the special tube required for this outfit had been perfected by the General Electric Co., and the instructions called for the purchase of 200 such tubes. Of these outfits, 80 were to be shipped to France and the remainder distributed within the United States. A further order for 150 bedside units was placed in March, 1918; subsequent orders raised the number to 547.

In procuring the various types of apparatus, delays in delivery were experienced. These delays for the most part were due to difficulties in getting raw materials and semifinished parts and to those incident to the congestion of the transportation lines. Some of the delays were due to faulty organization and factory operation, but those delays were eventually overcome and full cooperation was secured. While the prices for the large interrupterless apparatus varied somewhat with the different makes, the cost of this apparatus to the Government was reasonable and as a rule concessions were made.12


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DISTRIBUTION

As has already been indicated, each large hospital in the United States was provided with a standard interrupterless X-ray machine and complete outfit. The smaller hospitals were provided with appropriate equipment. The hospitals at the flying fields were furnished the standard bedside unit.13 The shipments of the standard interrupterless machines and other bulky pieces of apparatus were made direct from the makers to the hospital in which they were to be installed. Except for the delays incident to slow transportation, no inconvenience resulted. The apparatus was usually at the camp and installed as soon as the hospital was ready to function. The bedside units were all received at the New York depot, from which, with appropriate equipment, they were shipped to the hospital for which intended. In these shipments no special packing or arrangements were made other than those common among the makers.

The larger part of the equipment was intended for use and found its way overseas. The quantities sent overseas and those placed in use for domestic purposes appear below (p.600).

In preparing the equipment for shipment to France, special precautions were taken to make sure that the various parts of any particular equipment could be collected readily and the entire outfit assembled for issue. The plan adopted at the New York depot to meet this end is quoted below.

MARCH 12, 1918.

From:  Medical Supply Officer, United States Army, New York City.
To: Medical Supply Officer, Medical Supply Depot, American Expeditionary Forces, France.

Subject: Seventeen portable X-ray equipments.

1. We shipped you, on March 4, the 17 complete original portable X-ray equipments ordered last fall, in accordance with specifications issued at that time. For your convenience, these boxes were numbered according to a system devised to simplify their assembling into equipments.

2. Each piece is marked with an equipment number, denoted by a roman numeral, and a piece number, denoted by a regular arabic number. The equipments are numbered from 1 to 17 in roman numbers (I to XVII) and the piece numbers range from 1 to 13 in arabic numbers.

3. In assembling an equipment complete, for reshipment to a point in France, all that will be necessary will be to pick out an equipment marked with a roman number and the pieces marked with the arabic number from 1 to 13, as -

[CHART]


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[Page]


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Box No. 11:  3 stretcher tops and one stretcher top frame. (This material is for use with the portable table.)
Box No. 12:  Portable table, base.
Box No. 13:  Portable table, top.

5. We have shipped you, by registered parcel post, two separate boxes, each containing 17 padlock keys. These packages were marked, "Keys for paclock on portable darkroom carrying cases." These are for piece No. 2 in all the equipments.

6.  We have also shipped you 3 boxes, each containing 34 padlock keys, marked "keys for padlocks on carrying cases--portable X-ray outfits." These are for the carrying cases for the Coolidge tubes, pieces Nos. 4, 5, and 6, in all of the equipments.

7.  The keys shipped as mentioned above have been separated into different boxes to insure at least one set reaching you safely. They are interchangeable.

_____________ ____________
Colonel, Medical Corps, U.S.A.

The difficulties in obtaining the necessary pieces of apparatus to complete these equipments delayed the shipment of X-ray outfits to France. By the end of April, 1918, however, the following outfits had been delivered to Pier 45, North River, for shipment to France: 14 65 standard base hospital units, 17 standard portable outfits, 80 standard bedside units. Each of these outfits was complete when it left the depot. By the end of June the numbers had been increased to 100 base outfits, 97 portable outfits, and 165 bedside units.15 Complete information concerning each shipment was furnished the medical supply officer, A. E. F. By the end of the year the total shipped had reached those given in the column overseas on the list (p.600).

X-RAY TUBES

When the United States entered the World War two principal types of X-ray tubes were being purchased: A so-called gas tube and a Coolidge tube. The tendency appeared to be in favor of the Coolidge tube, but many of the roentgenologists who were called into the service were accustomed to using the gas tube, and that class of tube was purchased in considerable numbers. This tube had the further advantage that several firms were manufacturing it, and only one firm the Coolidge tube. Consequently, in equipping the hospitals with X-ray tubes it was decided to provide a proportion of both types. At this time only the large or standard Coolidge tube was being manufactured, and this required for its use devices for rectifying the direction of the current. With the development of the portable and the bedside units, smaller tubes, capable of rectifying their own current, were developed and later came to be supplied in large numbers. The respective numbers of Coolidge tubes and gas tubes purchased are given in the list of X-ray apparatus (p.600).

Inasmuch as platinum was required in varying amounts in the manufacture of the different types of tubes, the increasing platinum shortage made necessary a modification of the type of tube to be furnished. Because of the large quantities of platinum used in the platinum target tubes, manufacture of that type of tube was discontinued in favor of the tungsten target tube, there being no shortage of the latter metal. The quantity of platinum ultimately used in all makes of tubes was greatly reduced, it being found that even the platinum wire used, anode and cathode, could be materially reduced and still give satisfactory results.16 In the effort to conserve the supply of platinum all


597

broken X-ray tubes, especially those of the platinum target type, were salvaged and the metal parts turned in to the New York medical supply depot for the recovery of the platinum they contained.15

Tube makers were advised by the Surgeon General, March 28, 1918, to discontinue the manufacture of the platinum target tubes and air-cooled tubes and to confine manufacturing efforts to the tungsten target tubes only.17 On July 2, 1918, instructions were issued to the medical supply depot, New York, that all platinum-faced target tubes returned to the depot for repair were to be classified immediately as scrap regardless of the condition of the tube, and that no repair on tubes of that class would be authorized. No parts of these tubes was considered of any value except the target. The tubes were obsolete and the platinum exceeded the value of the tube.15 Previous instructions had been issued directing the platinum target tubes to be turned over to purchases of platinum as scrap.18 All platinum in the United States at that time was practically controlled by the Government. Scrap platinum thus turned in found its way back into articles containing platinum which were being manufactured for the Government. It was necessary to obtain priority for the platinum required for X-ray tubes being purchased.19 While at times there was a slight delay in obtaining these priorities, no material difficulty was experienced or undue delay therefrom.20

For a time the tubes were tested at the medical supply depot, New York, but later the practice was discontinued.21

DISTRIBUTION

As previously noted, the original requirements for all hospitals were met by shipment either from the New York medical supply depot or direct from the tube makers. A considerable breakage was reported in these tubes, and because of the transportation facilities the interval which elapsed between the time the tubes were forwarded for repair and their receipt back at the hospital became rather long. The need for a more prompt exchange of tubes was felt. To facilitate this exchange and to insure the more prompt arrival of the tubes at the requiring hospital, the Surgeon General issued instructions April 8, 1918, to the medical supply officers concerned to establish a stock of tubes at Chicago, Atlanta, San Antonio, and San Francisco.22 Ten tubes each, Coolidge medium focus and tungsten target 7-inch, were ordered to each of these depots, with instructions to issue the tubes only on approved requisitions to such posts as required them. They were directed to make requisition on the New York depot for requirements of this stock from time to time as issue made necessary.23 A minimum stock of three tubes was required. Whenever the stock was reduced to that number requisitions were forwarded for enough tubes to bring the stock up to 10 tubes of each type.

X-ray tubes turned in for repair were sent to the New York depot, where they were replaced by shipment of a new tube, and the damaged tube, if worth repairing, was sent to the manufacturer for repair.24 The original tubes, when repaired and received back at the New York depot, were placed in stock for reissue.25


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The number of X-ray tubes required in France was very large. Originally, they were prepared for shipment there in very light “bird-cage” crates, in which the tube was supported in place by a sling of ticking. These cages had projections at the bottom to prevent their being tipped over. It had been found that shipping them in the vertical position resulted in less breakage than in any other position, hence, the design of the crate. For various reasons, partly due to the manner in which these bird-cage carrying cases had been handled, a very extensive breakage was reported from overseas. A special box was designed to carry the tubes which it was thought would be sure to prevent the breakage. These special boxes consisted essentially of a strong outer box and an inner box suspended on springs. In the inner box the tube was placed, and supported as carefully as it could be. It was found that the breakage of tubes shipped by this method was considerably greater than that which resulted from the shipment in the light bird-cage crate. This was apparently due to the fact that in unloading it the stevedores did not recognize the fragile nature of the material and the boxes were handled more roughly. A drop of the box of a few feet was sufficient to break the tube. The breakage caused a great deal of anxiety to both the Medical Department and the General Electric Co., which supplied the tubes. It was decided to discontinue the use of the special box and to make all shipments in the bird-cage crate.26 An inspection of the loading procedures at the port of embarkation indicated that the tubes were very often laid on the side and that no precaution was taken to secure them in place. Other than this they were handled in a careful manner.27

At the request of the General Electric Co., authority was given that organization to direct the storing of this special type of cargo.28 Under this policy the tubes were practically the last articles of equipment to be loaded on the transport. They were stored between decks with life preservers and mattresses as dunnage. No winches were worked on the boat after the tubes had been placed aboard. The tubes were carried up by hand and carefully placed in the hold so that no breakage occurred in the loading. On the arrival of the transport overseas the tubes were unloaded before any of the other cargo was removed. As a result, the breakage was almost entirely eliminated.26 The tubes were shipped from the factory at Schenectady either by truck, if a truck train happened to be passing through on its way to New York, or by express.29 After delivery in France an equal amount of care was taken in handling them from base ports to supply depots, and thence to the hospitals which required them.

FLUOROSCOPIC SCREENS

After the early purchases, little difficulty was experienced in obtaining an adequate number of screens of suitable quality. As the quantities required increased, the difficulties in securing satisfactory screens increased in like proportion. Ultimately, however, a satisfactory screen was obtained in numbers to meet the demand.
 
As the X-ray work in the various camps developed, the number of plates required steadily rose. The demands for plates from overseas were also increasing. The requirements by the end of March, 1918, had risen to such heights


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that doubt began to be entertained concerning the ability of the manufacturers to obtain sufficient glass to meet them. With a view of reducing the consumption of plates the following instructions were issued:

APRIL 17, 1918.

From: The Surgeon General, United States Army.
To: All hospitals, and Cornell Medical College, Fort Riley, and Fort Oglethorpe.
Subject: Plates and films in X-ray work.

1. The question of an adequate supply of photographic glass suitable for coating in the making of sensitized X-ray plates is becoming a very pressing one. It may reasonably be expected that within a short time 14 by 17 plates will be practically unobtainable unless efforts are made to conserve this glass by avoiding the use of the smaller sizes of plates.

2. Fortunately, there has been developing a photographic film, double coated, and covered by an emulsion fully as sensitive and fast as that with which plates are coated. This film has many advantages. First, it is obtainable and will he obtainable. Second, its weight and bulk as compared to the corresponding quantity of plate surface is infinitely in its favor. Third, its cost is actually less than that of the photographic plates.

3. It is therefore desired by the X-ray division that requisitions from the various X-ray laboratories should call for increasing quantities of this special X-ray film and decreasing quantities of plates.

4. 14 by 17 plates for chest work will of necessity be furnished until such time as a satisfactory method of employing films for stereoscopic chest work has been devised.

5. The advantages of these films, aside from their lack of weight and bulk, are that they are actually faster than plates, that they are capable of giving beautiful detail, and that large numbers of films ean be developed in tanks or trays of small size. These films are particularly adaptable for gastro-intestinal work, and when used between two screens are exceedingly fast.

6. For shipment overseas these films may be expected to practically supplant plates for the reason that 100 dozen 10 by 12 films weigh less than 5 per cent and do not occupy more than 5 per cent of the space of the same quantity of ordinary glass plates.

7. Film holder to be employed in the development of these films will be supplied on requisition, and there will also be supplied with these films, and without requisition, a heavy opaque paper folder to be employed in place of the ordinary light-type envelope.

8. It is directed that great care be taken in the handling of these films to avoid finger marking the emulsion and kinking the celluloid upon which the gelatine emulsion is coated.

9. Where these films are employed in the ordinary black and orange envelopes care must be taken to avoid surface scratching by the edges of the envelope, which scratches will appear as black streaks upon development.

Prior to 1917 the principal dependence in X-ray work had been upon plates. X-ray films were but little used except in dentistry. Developments were in progress, however, even then, for the production of the larger size films required for X-ray work. Samples were submitted by the manufacturers and found very satisfactory in stomach and gall-bladder work and for other equally exacting requirements.30 They began to be used in increasing quantities in the Army. They were sent in increasing proportion to France. The earlier shipments were mostly plates, but the later shipments gave preference to films. By the end of April, 1918, 9,130 dozen films, assorted sizes, 5 by 7 inches, 8 by 10 inches, 10 by 12 inches, 11 by 14 inches, and 14 by 17 inches, had been shipped to France. During the same period 7,346 dozen plates, in sizes, 8 by 10 inches, 10 by 12 inches, and 14 by 17 inches, had been forwarded. The dental films during that period numbered 3,280 dozen.14 The total number of plates and films purchased during the World War period is shown in the table (p.600.)


600

An investigation of the glass and X-ray plate situation made during the early part of August showed the shortage of plates from which the Medical Department had been suffering for several months was more apparent than real.31

The American Window Glass Co., makers of the glass used in X-ray plates, promised all the glass necessary, and further difficulties along that line were eliminated.31 Orders were placed the latter part of August for 1,400 dozen plates per month distributed in the proportion of 600 dozen 14 by 17 inches, 400 dozen 10 by 12 inches, and 400 dozen 8 by 10 inches. The order was to run for a year.32

CANCELLATIONS FOLLOWING SIGNING OF THE ARMISTICE

Immediately following official information of the signing of the armistice, machinery was set in motion for the termination of unfilled contracts for X-ray equipment and supplies.33 In the negotiations for the settlement of these contracts varying proportions of the contracted materials were accepted and the remainder canceled. Such quantities as the future needs seemed to indicate as desirable were furnished the contracting officer, and the settlement of all such contracts was effected in due course and without difficulty.

X-ray apparatus contracted for and distributed up to November 25, 1918


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REFERENCES

(1) Letter from Arthur C. Christie, to Col. Edwin P. Wolfe, M. C., January 15, 1921. Subject:  Account of X-ray apparatus used by the U. S. Army in the World War. On file, Finance and Supply Division, S. G. O., 808 X-ray/100A.
(2) Letter from Dr. Lewis Gregory Cole, Chairman, Committee on Preparedness, American Roentgen Ray Society, to Col. Fisher, S. G. O., War Department, April 27, 1917. Subject: X-ray apparatus. On file, Finance and Supply Division, S. G. O., 14744-A.
(3) Letter from A. D. Ballou, Council of National Defense, to Lieut. Col. Fisher, M. C., S. G. O., May 1, 1917. Subject: X-ray apparatus. On file, Finance and Supply Division, S. G. O., 14744-C.
(4) Letter from the medical supply officer, U. S. Army, New York, to the Surgeon General, U. S. Army, August 11, 1917. Subject: Places to be furnished with stationary X-ray apparatus. On file, Finance and Supply Division, S. G. O., 713-539/144.
(5) First indorsement, Surgeon General, to the officer in charge, Medical Supply Depot, New York. On file, Finance and Supply Division, S. G. O., 713-539.
(6) Letters from Maj. A. C. Christie, Reserve Corps, to various light and power companies in the United States, June 2, 1917, relative to type, voltage, and cycle of current furnished by them. On file, Finance and Supply Division, S. G. O., 14846-D to I.
(7) Letter from the Surgeon General to the officer in charge, Medical Supply Depot, New York, October 25, 1917. Subject: X-ray apparatus for 100 base hospitals. On file, Finance and Supply Division, S. G. O., 808 X-ray/15.
(8) Letter from the Surgeon General to the officer in charge, Medical Supply Depot, New York, November 1, 1917. Subject: X-ray apparatus for 100 base hospitals. On file, Finance and Supply Division, S. G. O.,  808 X-ray/15.
(9) Letter from Maj. A. C. Christie, M. R. C., to Col. H. D. Snyder. August 23, 1917, relative to the purchase of X-ray equipment. On file, Finance and Supply Division, S. G. O., 713-539/56.
(10) Letter from the Surgeon General to the officer in charge, Medical Supply Depot, New York, November 28, 1917. Subject: Portable X-ray apparatus. On file, Finance and Supply Division, S. G. O.,  250 Fr/133.
(11) Letter from the Surgeon General to the officer in charge, Medical Supply Depot, New York, September 13, 1917. Subject: X-ray supplies. On file, Finance and Supply Division, S. G. O.,  713-539/122.
(12) Letter from Major A. C. Christie, M. R, C., S. G. 0., to the Wappler Electric Company, New York, N. Y., June 5, 1917, relative to X-ray machines. On file, Finance and Supply Division, S. G. O., 14846-N.
(13) Letter from the Surgeon General to the officer in charge, Medical Supply Depot, New York, October 16, 1917. Subject: X-ray apparatus for  aviation camps. On file, Finance and Supply Division, S. G. O., 808 X-ray/1.
(14) Report on X-ray apparatus, equipment, and supplies, shipped from Medical Supply Depot, New York to France, embracing period from July 1, 1917, to April 27, 1918. On file, Finance and Supply Division, S. G. O., 713-539 NYD/648.


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(15) Third indorsement, Surgeon General, to the officer in charge, Medical Supply Depot, New York, July 2, 1918, relative to X-ray tubes turned in for repair. On file, Finance and Supply Division, S. G. O., 713-539 NYD/774.
(16) Letter from Green & Bauer (Inc.), Hartford, Conn., to G. C. Johnston, major M. H. C., S. G. O., March 26, 1918, relative to platinum in X-ray tubes. On file, Finance and Supply Division, S. G. O.,  291 G & B/1.
(17) Letter from Maj. Geo. C. Johnston, M. R. C., S. G. O., to E. Matchlett & Sons, New York City, March 20, 1918, relative to manufacture of platinum-faced target X-ray tubes. On  file, Finance and Supply Division, S. G. O.,  463 E.M.C/1.
(18)  First indorsement, Surgeon General, to the officer in charge, Medical Supply Depot, New York, June 24, 1918, relative to disposition of platinum from X-ray tubes turned in. On file, Finance and Supply Division, S. G. O., 713-539 NYD/774.
(19) Letter from Lieut. Col. A. C. Christie, M. C., N. A., S. G. O., to the General Electric Co., Schenectady, N. Y., March 12, 1918, relative to priorities. On file, Finance and Supply Division, S. G. O.,  263 G.E. Co./10.
(20) Telegram from F. M. Hoben, General Electric Co., New York, to Lieut. Col. A. C. Christie, S. G. O., March 21, 1918, relative to platinum. On file, Finance and Supply Division, S. G. O., 713-539/7.
(21) Letter from the medical supply officer, New York City, to Maj. George C. Johnston, S. G. O. April 25, 1918. Subject: Testing Coolidge tubes. On file, Finance and Supply Division, S. G. O.,  713-539 N. Y./574.
(22) Letter from the Surgeon General to the officer in charge, Medical Supply Depot, New York, April 8, 1918. Subject: Supply of X-ray tubes. On file, Finance and Supply Division, S. G. O.,  713 Misc./37.
(23) Letters from the Surgeon General to the officers in charge, Medical Supply Depots, Atlanta, Chicago, San Antonio, and San Francisco, April 8, 1918. Subject: Supply of X-ray tubes. On file, Finance and Supply Division, S. G. O.,  713 Misc./37.
(24) Letter from the Surgeon General to the officer in charge, Medical Supply Depot, New York, N. Y., May 25, 1918. Subject: Coolidge tubes for issue from Supply Depots. On file, Finance and Supply division, S. G. O., 713 Misc.
(25) Letter from the Surgeon General to the officer in charge, Medical Supply Depot, New York, July 6, 1918. Subject: Procedure in replacement of X-ray tubes returned for repair. On file, Finance and Supply Division, S. G. O., 713-539 N.Y.D./806.
(26) Letter from Lieut. Col. George C. Johnston, M. C., U. S. A., to Mr. K. S. Kendrick, General Electric Co., Supply Department, Schenectady, N. Y., October 4, 1918, relative to overseas shipment of X-ray tubes. On file, Finance and Supply Division, S. G. O., 263 G.E. Co./34.
(27) Letter from Supply Department, General Electric Co., Schenectady, N. Y., to Lieut. Col. A. C. Christie, S. G. O., June 6, 1918, relative to loading of X-ray tubes on ships. On file, Finance and Supply Division, S. G. O., 263 G. E. Co./25.


603

(28) Fourth indorsement, from the commanding general, Port of Embarkation, Hohoken, N. J., to chief of Embarkation Service, Washington, D. C., June 22, 1918, relative to loading  X-ray tubes for overseas shipment. On file, Finance and Supply Division, S.G.O.,  263 G. H. Co./25.
(29) Letter from Howard W. Dunk, 604 West One hundred and twelfth Street, New York, N. Y., formerly sergeant, first class, Medical Department, to Col. Edwin P. Wolfe, M. C., May 7, 1927, relative to the operation of the X-ray department, Medical Supply depot, New York, 1917-18. Data compiled from depot records. On file, Finance and Supply Division, S. G. O.,  713-539 N.Y../1243.
(30) Letter from Maj. A. C. Christie, M. R. C., S. G. O., to Eastman Kodak Co., Rochester, N. Y., June 30, 1917, relative to X-ray plates. On file, Finance and Supply Division, S. G. O.,  55 Misc./1.
(31) Memorandum for Colonel Darnall from Maj. George Johnston, M. R. C., August 8 1918. Subject: Shortage of X-ray plates. On file, Finance and Supply Division, S. G. O.,  750-714 SG/635.
(32) Letter from the Surgeon General to the officer in charge, Medical Supply Depot, New York, August 19, 1918. Subject: Contract for X-ray plates. on file, Finance and Supply Division, S. G. O.,  713-539 N.Y./901.
(33) Letters from the Surgeon General to the officer in charge, Medical Supply Depot, New York, November 13, 1918, relative to cancellation of contracts. On file, Finance and Supply Division,, S. G. O., 713-539 N.Y./1160-1164.