68 Prof. Loomis on Bodies falling through the Atmosphere. 
descent became sensibly uniform after a fall of 40 feet; and in 
the second series of experiments after a fall of 10 feet. I care- 
fully computed the time of descent through the space just men- 
tioned, and dividing the remaining distance by the remaining 
time of descent, obtained the terminal velocity, from which the 
coefficient of resistance is easily deduced. 
In these computations I made use of Hutton’s formule which 
are as follows; 



Agce — oo < 
“Tat eae log. — Ta = h. log. N, 
1 N-1l 
er Ne cae ; 
w 
1 Ww Site 
=a. 2x h. log. a 
PES 
w 
eke 5 
Where 
c = the coefficient of resistance, 
g = 16,, feet, 
w = the weight of the body expressed in ounces, 
x = the space fallen through, 
v = the velocity acquired in falling through the space z, 
¢ = the time of descent through the space x 
v’ = the terminal velocity of the body. 
The following Table shows the results deduced from the first 
series of experiments with glass globes. Column first shows the 
weight of the globes in grains; column second shows their diam- 
eters in inches; column third shows the entire time of falling 
from a height of 220 feet; column fourth shows the velocity ae 
quired in falling through a space of 40 feet; column fifth shows 
the time of falling 40 feet ; column sixth shows the coefficient of 
resistance deduced from the time of descent; and column seventh 
shows the same coefficient reduced to a sphere of 5 inches i 
diameter by assuming the resistance to vary as the square of the 
diameter. 8 | 


A NEAR. IA A ee 
| 









| Weights of \Diamet'rs of Whole times Velocity in |Time of fall-| Coefficient Do. reduced to8} 
the globes. | the globes. | of falling. | falling 40 ft.| ing 40 feet, | of resistance. | sphere of 5 im+| 
grains. inches, 8. 8, : 
510 51 82 28-237 1:9967 13845 0013307 
642 52 TT 30-026 1-9386 0015033 0013899 
599 51 wa 30070 1/9373 14033 0013488 
B15 5: 7:95 29°188 19650 0013014 0013014 
chad 5 ve 28°383 19917 0013133 0018 te 
1 52 i 30°099 1°93 "0015022 0018 


