AUTOMATIC SIGHTING-. 
135 
levelling will be provided.* On the second point therefore we 
find the automatic sight again on an equality with the range-finder. 
There are in addition some reasons why automatic sights should give 
greater accuracy than any range-finder. 
They are as follows :— 
(1.) As there is a sight to each gun, each sight can be set, by 
means of the error of the day ” screw and adjusting foresight, to 
accommodate itself to any idiosyncracies of its own gun, or any 
peculiarities of its own layer. This can be done, with the help of 
trial shots, at any time before actiom 
(2.) There is only one personal error to affect the shooting—that 
of the layer—in place of two where a range-finder is used, those of the 
observer and gun captain (or layer) which may be cumulative. 
(3.) That part of the gear of the service automatic sight which 
is essential to its accuracy as a range-finder is so extremely simple 
and strong, and works with such directness and absence of interven¬ 
ing parts, that there is apparently nothing which wear and tear can 
act on to produce error. 
(4.) Automatic sights eliminate tidal errors. A range-finder 
can, of course, be corrected for height of tide, but there is still the quad¬ 
rant elevation scale of the gun, which is graduated for mean tide, and 
must remain so. An error is, therefore, inevitable at all states of tide, 
excepting mean, decreasing with a higher site, increasing with a 
lower one, and only to be eliminated altogether by the clumsy method 
of making corrections in the range given by the range-finder. With 
automatic sights, on the other hand, tidal corrections are made, both 
as affecting the range-finding properties of the sight, and as affecting 
the quadrant elevation given to the gun, by the simple action of 
setting the tide lever. 
(5.) Lastly, there must be added to the above the immunity, 
which is enjoyed when using automatic sights, from the mistakes of 
drum readers, dial numbers, gun group commanders, gun captains, or 
of the dials themselves. An inspection of any accurately kept practice 
report brings home to one pretty clearly what it means to get rid of 
all these possible sources of error. 
III.—Diminished liability to disorganization of a 
command from hostile fire. 
A range-finder (at all events inspection of our coast fortresses would 
make it seem so) must necessarily be so placed that no intelligent 
enemy could fail to detect it at once. The compliments his Q.F. and 
machine guns might be expected to pay it would probably soon dis¬ 
organize it and its operators, with the result of disorganizing also a 
group and perhaps a whole battery command. Automatic sights on 
the other hand can be so shielded as to make them and their layers 
comparatively safe from machine and light Q.F. guns; and if one is 
* See “ Changes in wav materiel,” § 9380, February, 1899. 
