Viewing page 201 of 212

This transcription has been completed. Contact us with corrections.

78.

for time just under 1/2 sec., v'=293.1 ft/sec; s=91.98 ft.

""""[[ditto for: for time just under]] 1 "[[ditto for: sec.,]] v'[[subscript]] 0 [[/subscript]]=603.8 ft/sec; s=335.48 ft.

and """"[[ditto for: for time just under]] 2 "[[ditto for: sec.,]] v'[[subscript]] 0 [[/subscript]]=1284.1 ft/sec; s=1315.68 ft.

These figures compare well with those in Table V, for [[underlined]] s [[/underlined]][[subscript]] 1 [[/subscript]]. In the present check, air resistance would doubtless be unimportant until the velocity has reached 1,000 ft/sec. or so; but the velocity would, even if decreased somewhat by air resistance, compare favorably with that of a projectile fired from a gun.

No more elaborate calculation is necessary to demonstrate the importance of the device, even military purposes alone; for it combines portability and cheapness (no gun required for firing it) with a range which compares favorably with the best artillery. Further, all difficulties of the nature of erosion are, of course, avoided.   

Transcription Notes:
That last paragraph was pretty prophetic! You said it :-)