The Mechanical David 



Centrifugal force propels the bullets towards the enemy 

 with terrific force, at the rate of 20,000 a minute 



THE present world war has brought 

 out so many striking reversions to 

 primitive principles and methods 

 of attack and defense that the invention 

 of a gun based upon 

 the same principle that 

 enabled David to lay 

 low the mighty Goli- 

 ath, should, by rights, 

 cause no particular 

 surprise. The gun, 

 which is shown in the 

 accompanying illustra- 

 tion, is the invention 

 of Levi W. Lombard 

 of Boston, Mass. Its 



W-5" 



general appear- 

 ance is more 

 that of a feed 

 cutter or coffee- 

 mill, but it is 

 said to be cap- 

 able of firing 

 20,000 projec- 

 tiles a minute with sufficient force to 

 penetrate steel plates three quarters of 

 an inch thick at a distance of several 



hundred feet, a noteworthy achievement. 

 The Lombard gun is based upon the 

 principle of centrifugal force. A disk, 

 twelve inches in diameter, which is rotated 

 at the rate of 20,000 

 revolutions a mmute, 

 has a curved ridge 

 from its center to op- 

 posite points of its 

 periphery. The ridge 

 has a groove on one 

 side, which forms the 

 channel for the bul- 

 lets. These are fed 

 from the center of 

 the disk, one at every 



o «4Di5K9vn Looking down into the hop- 

 per from which the bullets 

 are fed to the rapid-fire gun 



V 



Photo3 @ lilt. Film S.rv. 



The disk of the gun may be revolved by an elec- 

 tric motor, a gasoline engine or by hand power 



revolution and are expelled by the centrif- 

 ugal force of the revolving disk. The 

 bullets leave the gun all in the same 

 plane, but not all in the same 

 direction. They come through 

 a slit in the casing of the re- 

 volving disk, which represents 

 about five degrees of the per- 

 iphery. Actual tests have shown 

 that the linear velocity of the 

 bullets (2000 feet per second) 

 is greater than the velocity of 

 the disk. 



It is stated that, no matter 

 what may be the speed of the 

 disk, the bullets always come 

 out at the same place. This 

 result, which involves compli- 

 cated mathematical and me- 

 chanical problems, is obtained 

 by the feeding mechanism and 

 the peculiar form of the curve 

 of the grooved ridge. One of 

 the illustrations shows a top 

 view of the feeding hopper. 

 The gun may be revolved by 

 an electric motor, a gasoline 

 engine or by hand power. 



699 



