222 
THE VALUE OF A HIGH SITE FOR COAST ARTILLERY. 
Then as e must be greater than e , let 
e=ne' where n is>l. 
Let the virtual targets be DV and DV' as in fig. 5, 
then 
D FETUS'sin co, 
or 
and 
or 
a cos co + 6 sin co = esinco; 
DV'=DE' sin 8, 
and 
a cos 8 + 6 sin 8 = e' sin 8; 
% (a cot 8 + 8) = a cot co + 8: 
cot CO + - 
a 
n = 
cot 8 + - 
a 
(Art. II.) 
(Art. II.) 
By comparing n with the corresponding value of m, we can see 
whether it would require a greater mistake to cause e' than that which 
would cause e. 
Fig. 6. 
Thus if n = m, then the same mistake would have the same result 
in each case; if n is > m, then the same mistake would be more 
detrimental in the case of the high site, than in the ease of the low; 
if n is < m the reverse is the case. 
