Fig. 
4 
rOPULAR SCIENCE REVIEW. 
(March 21, 1864.) — “Soon after his 
appointment, Professor Bashforth, in his 
first letter to the Ordnance Select Com- 
mittee, recommends the adoption of a 
kind of printing telegraph . ... in order 
that we may have a check upon the 
measurements of striking velocities .” It 
goes on to state, page 25 : “As this sug- 
gestion did not appear to meet with ap- 
proval, it devolved upon Mr. Bashforth 
to carry out his own plans, which have 
now been brought to a successful termi- 
nation after four years of incessant la- 
bour.” (July 23, 1868.) In the same 
page the Beport further declares : “ The 
state of our knowledge of the resistance 
of the air in 1865 was well expressed in 
Captain W. H. Noble’s Beport to the 
Ordnance Select Committee dated April 
2, 1865 : — “It is regretted that this sub- 
ject cannot be fully treated in the present 
Beport, but the difficulties in the way of 
a clear solution are so many and so great, 
that it would be difficult with our present 
experience to assign any new law repre- 
senting with accuracy the resistance of 
the air to the motion of spherical and 
elongated projectiles’” (page 19). 
The scientific referees thus characterise 
the Bashforth instrument : — 
“We do not think that any means be- 
fore existed of recording a number of 
successive small intervals of time with the 
degree of precision and trustworthiness 
attained by Professor Bashforth’s instru- 
ment.” 
% % % % 
This instrument gives records in paral- 
lel spiral lines traced on a revolving 
cylinder : — (1) of every alternate beat of 
a half-seconds clock ; (2) of the instants 
in 2,000ths of a second of the ball 
cutting threads in ten to fifteen screens 
placed 50 — 150 feet apart. 
The accompanying diagram is a re- 
duced facsimile of the record of an ob- 
served round of firing cannon-shot through 
the screens. 
