282 
PRINCIPLES OE GUNNERY. 
The little extra distance due to a fall of 8 ft. may be approximated 
to by 
A" = 8 cot 5° = 8 x 11*43 = 91*4 ft. 
Now, 
X = 3441 
X' = 2914 
X " = 91 
Again, 
or total range = 6446 ft. = 2148*6 yds. 
^' = !(4'5“4b) 
= 2*81 secs. 
T 9 5 S . 5 = 4*0137 
Tn68 = 1*9081 
2*1056 
4 
3)8*4224 
2*8074 
The little extra time taken to travel over X"= 91 ft. may be approxi¬ 
mated to by dividing the distance by the velocity at end of the arc of 
5°— i.e., by v’ = 953 f.s .; or 
Now, 
91 
953 
= *095. 
T =2*48 
r = 2*81 
T" = *09 
or total time of flight = 5*38 secs. 
In practice with this gun at Shoeburyness under similar conditions, 
the mean range of 10 rounds was found to be 2128 yds.—-the maximum 
being 2161 yds. and the minimum 2097. The mean time of flight was 
observed to be 5*5 secs. 
An example oe the approximate solution op high-angle trajec¬ 
tories WILL NOW BE GIVEN. 
Example (2).—The 8-in. M.L. howitzer is fired at an angle of quad¬ 
rant elevation of 30°, and jumps 1°. What will be the range and time 
of flight? Muzzle velocity = 745 f.s., weight of shell = 180 lbs., dia¬ 
meter of shell =7*92 ins. 
The most correct way of solution would be to divide the ascending 
branch into three or more component arcs, and compute over each arc ; 
and in the same way with the descending branch. But this would 
