A METHOD OF RECORDING BY PHOTOGRAPHY THE DEGREE OF ACCURACY IN AIMING ORDNANCE
Year: 1885

page_text: WAT
I, CHARLES WELLS, of 18, Walker Terrace, Plymouth, in the County of Devon,
Gentleman, do hereby declare the nature of my invention for " A METHOD OF
RECORDING BY PHOTOGRAPHY THE DEGREE OF ACCURACY IN AIMING ORDNANCE,"
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:—
In ordnance drill at moving objects without cartridge, the gunner and his
instructor are, both, without any record of the degree of inaccuracy in the aim
taken. The aim may be very wide, or only a little out, but neither the novice,
nor his instructor, can use the amount of error in the last aim, as an exact basis of
calculation for making the next one more accurate.
My invention aims at overcoming the drawbacks described above as incidental
to ordnance drill, as at present conducted, and consists in the adaptation of a
photographic apparatus to the piece with which practice is being made. The
camera is made to expose its plate at the moment of firing, and the plate being
what is known as an instantaneous one, an accurate picture of the relative position
of the moving object with respect to the line of fire at the moment, is obtained,
thereby recording at once the degree of accuracy of the aim taken for that fire.
In order that my invention, and the means by which it may be put into
succesful operation, may be thoroughly understood, I will proceed to describe the
same in detail, referring in so doing to the accompanying drawing which is to be
taken as part of this specification and read therewith.
A is the gun; B the moving object a.g. a ship; and, C, the true line of fire.
D is a camera fixed at the side, or on the top, of the gun, so as to be out of the
line of sighting, at or near, the vertical plane which passes through the trunnions
of the gun. The camera is fitted with its sensitive plate of glass, paper, or suitable
equivalent material. The instantaneous shutter has a series of fine wires passing
across its field, after the manner of the object glass of a theodolite. These are
preferably numerous, and crossing each other so as to divide up the field up into
measurable areas and distances. I arrange that one intersection should mark the
axial centre of the field, or this can be marked by a spot.
The above markings may be made upon the plate before it is placed in the

page_text: camera, it being necessary, however, that care should be taken in putting the plate
into the camera that the central intersection, or mark, should coincide with the
axis of the lens.
The shutters, d, of the camera, D, is raised by the act of pulling the fuse, a
suitable connection being established between the two as indicated by the line, f.
This connection is of any convenient type, and is, of course modified according to
the kind of fuse and of shutter employed, I do not confine myself to the position
of the camera shewn in the drawing, as it may be at either side of the gun,
provided that the axial lines of both gun and camera meet in the object aimed at,
or any divergence may be allowed for in the adjustment of the markings on the
plate, or wiring, of the shutter, or in the subsequent calculations.
When the camera is carried on the top of the gun, it is always fixed at such a
height that its presence does. not obstruct the "sighting."
Having now particularly described, and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that
what I claim is
The combination of camera with reticulated or marked field or plate, and a
shutter capable of being operated by the act of firing the gun, the whole for the
purpose of photographically registering the degree of accuracy of the gunner's aim,
substantially as described with reference to the accompanying drawing.
+ 11° 200
T
100K
PHILLIPS & LEIGH,
Patent Agents,
22, Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicant.