As soon as our officers in France could make an adequate study of our aircraft needs in machine guns, they discovered that in the three years of war only one weapon had met the requirements of the allies for a fixed machine gun that could be synchronized to fire through the whirling blades of an airplane propeller. This was the Vickers gun, which was already being manufactured in some quantity in our country, and for which three months before we entered the war we had given an order amounting to 4,000 weapons. On the other hand, the fighting aircraft of Europe were also finding an increased need for machine guns of the flexible type—that is, guns mounted on universal pivots, and which could be aimed and fired in any direction by the second man, or observer, in an airplane. The best gun we had for this purpose was the Lewis machine gun.
For technical reasons that need not be explained here, the Vickers gun was a difficult one to manufacture. The Colt Co., which was producing these weapons, in spite of their long experience in the manufacture of such arms and in spite of their utmost efforts, had been unable to deliver the finished Vickers guns on time, either to the Russian government or to this country. However, by expanding the facilities of this factory to the utmost, by the month of May, 1918, the concern achieved a production of over 50 Vickers guns per day. Doubtless, because of these same difficulties, neither the British nor the French governments had been able to procure Vickers guns as rapidly as they expanded the number of their fighting aircraft, and consequently when we entered the war we received at once a Macedonian cry from the allies to aid in equipping the allied aircraft with weapons of the Vickers type. An arrangement was readily reached in this matter. Our first troops in France needed machine guns for use on the lines. Our own factories had not yet begun the production of these weapons. Accordingly, in the fall of 1917, we arranged with the French high commissioner in this country to transfer 1,000 of our Vickers guns to the French air service, receiving in exchange French Hotchkiss machine guns for Gen. Pershing's troops.
Now while the demands of the allied service had brought forth only the Vickers machine gun as a satisfactorily synchronized weapon, we, shortly after our entry into the war, had succeeded in developing two additional types of machine guns which gave every promise of being satisfactory for use as fixed synchronized guns on airplanes. One of these, of course, was the heavy Browning gun, stripped of its water jacket; but because this was a new weapon, requiring an entirely new factory equipment for its production, the day when Brownings would begin firing at the German battle planes was remote, indeed, as time is reckoned in war.
On the other hand, our inventors had been improving a machine gun known as the Marlin, which was, in fact, the old Colt machine gun, Mr. Browning's original invention, but now of lighter construction and with a piston firing action instead of a lever control. In the face of considerable criticism at the time, we proposed to adapt this weapon to our aircraft needs as a stop-gap until Brownings were coming from the factory in satisfactory quantities. We took this course because we were prepared to turn out quantities of the Marlin guns in relatively quick time. As has been said, the Marlin resembled the Colt. The Marlin-Rockwell Corporation was already tooled up for a large production of Colt guns, and this machinery with slight modifications could be used to produce the Marlin.
We decided upon this course shortly after the declaration of war, and there followed a severe engineering and inventive task to develop a high-speed hammer mechanism and a trigger motor which would adapt the gun for use with the synchronizing mechanism. But then occurred one of those surprising successes that sometimes bless the efforts of harassed and hurried executives at their wits' end to meet the demand of some great emergency. The improvements added to the Marlin gun eventually transformed it in unforeseen fashion into an aircraft weapon of such efficiency that not only our own pilots but those of the French air forces as well were delighted with the result.
When it was proposed to adapt the Marlin gun for synchronized use on airplanes, the Ordnance Department detailed officers to cooperate with the Marlin company in its efforts. For technical reasons of design the original gun apparently had little or no adaptability to such use. Many new models were built only to be knocked to pieces after the failure of some feature to perform properly the work for which it was designed. Nevertheless the enthusiasm of the company for its project could not be chilled, and it continued the development until the gun finally became a triumph in gas-operated aircraft ordnance.
In the latter part of August we were using the Marlin gun at the front, and cablegram after cablegram told us of the surprisingly excellent performances of this weapon in actual service. It is sufficient here to quote one of these messages from Gen. Pershing, dated February 23, 1918:
MAXIM MACHINE GUN AND TRIPOD (AMERICAN), MODEL 1904 CALIBER .30.