Improvements in Surveying Instruments.
Year: 1894

page_text: Date of Application, 12th Nov., 1894
Complete Specification Left, 9th Aug., 1895-Accepted, 21st Sept., 1895
PROVISIONAL SPECIFICATION.
Improvements in Surveying Instruments.
I, MATTHEW HENRY PHINEAS RIALL SANKEY, of Ferry Works, Thames
Ditton, in the County of Surrey, Engineer, (a communication to me from abroad
by Frederick William Moffitt, Lieutenant Essex Regiment now stationed at
Shahjahanpur North West Province India) do hereby declare the nature of this
invention to be as follows:-
The instrument is in two parts :-a board and a spring clip.
One side of the board is ruled with a number of parallel lines and the other side
has fixed to it the paper on which the plan is to be drawn.
The clip consists of two plates or legs connected together at one end, each being
about as long as the diagonal of the board. One leg is graduated and forms a rule
whilst the other leg carries a compass, a mirror and a pair of sights. The mirror
is either fixed or can be turned so as to be above the compass and make an angle
of 45° with the plane of the leg. The latter also has projecting slightly from its
inner face a point or centre which is directly opposite the zero on the scale on the
other leg.
The clip is such that it can be sprung onto the board with one leg on each side
and the legs can be held wide enough apart to keep the point out of contact with
the board and when this is done the clip can be moved in any direction but when
the leg carrying the point is allowed to bear on the board the point enters it and
then the clip can only be revolved on the board about the point and the scale
therefore moves about its zero as a centre.
The instrument is used as follows:-The clip is sprung onto the board with its
graduated leg on the paper and it is moved as above described until the zero of the
scale coincides with the point on the paper representing the observers station.
The sights on the other leg are directed to the object whose position is to be
plotted and at the same time the compass observed in the mirror whilst the clip
is held in this position the board is turned until the lines upon it are parallel to the
compass needle. A line then drawn on the paper along the end of the rule
correctly represents the direction of the object and its distance when known can
be marked by the graduations.
Dated this Tenth day of November 1894.
Improvements in Surveying Instruments.
I, MATTHEW HENRY PHINEAS RIALL SANKEY, of Ferry Works, Thames
Ditton, in the County of Surrey, Engineer, (a communication to me from abroad
by Frederick William Moffitt Lieutenant Essex Regiment now stationed at
Shahjahanpur North West Province India) do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
Figure 1 is an underside view and Figure 2 a side elevation of the instrument.
It is in two parts:—a board and a spring clip.

page_text: The underside of the board a is ruled with a number of parallel lines and the
other side has fixed to it the paper on which the plan is to be drawn.
The clip consists of two plates or legs bb connected together at one end each
being about as long as the diagonal of the board. The leg is graduated and
forms a rule whilst the other leg carries a compass c, a mirror d and a pair of
sights e e, in the instrument shown one of these is a notch on the back of the
mirror which forms a cover for the compass, the other sight is shown separately
in front elevation at Figure 3. The mirror d is either fixed or can be turned so as
to be above the compass and make an angle of 45° with the plane of the leg b
The latter also has projecting slightly from its inner face a point or centref which
is directly opposite the zero on the scale on the other leg.
The clip is such that it can be sprung onto the board with one leg on each side
and the legs can be held wide enough apart to keep the point out of contact with
the board and when this is done the clip can be moved in any direction but when
the leg carrying the point is allowed to bear on the board the point enters it and
then the clip can only be revolved on the board about the point and the scale
therefore moves about its zero as a centre.
The instrument is used as follows:-The clip is sprung onto the board with its
graduated leg on the paper and it is moved as above described until the zero of the
scale coincides with the point on the paper representing the observers station.
The sights on the other leg are directed to the object whose position is to be
plotted and at the same time the compass is observed in the mirror, whilst the clip
is held in this position the board is turned until the lines upon it are parallel to the
compass needle. A line then drawn on the paper along the end of the rule correctly
represents the direction of the object and its distance when known can be marked
by the graduations.
To provide for cases in which the map is required to be at any special angle to
the north the mirror d and sights e are carried by a bar g terminating in a strap gl
embracing the compass so that the bar with the sights can be turned about the
compass as a pivot, a set screw h being provided to fix it in any position. In using
this adjustment the north line is drawn in and the ruleb placed along it, the arm y
is then turned through the smallest angle to get it parallel to the lines on the board
and clamped and then the observations are recorded as before.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what
claim is :-
:-
1. The clip carrying sights and magnetic compass and having two legs to embrace
the board.
2. Surveying instruments substantially as described and shown in the drawings.
Dated this 1st day of August 1895.
M. H. P. R. SANKEY.