Year: 1895

page_text: Date of Application (in United Kingdom), 2nd Jan., 1895
Complete Specification Left, 2nd Jan., 1895-Accepted, 2nd Feb., 1895
I, LUDOVIC PICARD of 42 Boulevard Bonne Nouvelle, Paris, France, 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 :-
The object of this invention is the construction of a new drawing instrument by
means of which I can fix exactly after Nature and at any scale all the points
required in perspective or otherwise. In order to clearly understand the nature of
my invention I have represented it by the annexed drawing on which :
Figure 1 is a view in elevation of the instrument in question.
Figure 2 represents an example of its application for taking a perspective view
of houses.
The apparatus is composed
1st of three rulers or bars A B and C jointed at M and N to the ruler or bar A.
2nd of a wire or cord with a weight P the cord being attached at the joint M.
These three rulers or bars carry centrally an index () and are graduated into
centimetres with subdivisions in millimetres or equivalent indices.
The two rulers or bars A and B each have a longitudinal slot which allows them
to be displaced at will on the axis M.
This instrument now described is strong and simple in construction and the
operation is as follows:-
After having drawn on the paper the line representing the horizon, or in other
terms the imaginary horizontal-plane passing at the height of the eye of the
operator, the latter places vertically the branch A of the apparatus Figure 2 in
such manner that the cord or wire with the weight P comes perfectly in the middle
of the said branch A and taking care that the zero is at a level with the eye, that
is to say, in the plane of the horizon.
Then he notices one of the principal lines-a roof for example-above the horizon
and notes its coincidence with one of the divisions of the ruler A; he then brings
down the branch B to the height of this division in such a manner that it corresponds
with the inclination of the contour observed.
After having noted on the divisions of the ruler B the most distant point from
this inclined contour he places it on his paper care being taken to make coincide
the zero of the ruler A with the horizontal previously traced on the same paper.
By repeating several times the same operation either to the right or to the left
of the vertical ruler A and by turning the ruler B he can obtain all the points
which he considers necessary to reproduce on his sketch.
He then operates similarly with the ruler C to reproduce all the lines at the
principal points situated below the horizon.

page_text: The rulers being divided in centimetres and millimetres or the like it is easy
according to the scale adopted to reduce or increase the relative lines on the said
rulers in such manner that whatever may be the dimensions of the objects to be
drawn in perspective one can without difficulty effect the drawing and reduction
according to the scale that one may choose.
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 I
claim is :-
1. An instrument specially designed for drawing in perspective and after Nature,
and characterized by three rulers or bars jointed and adapted to slide on one
another to establish the inclinations of the lines and the situations of the principal
points placed above and below the horizon, the said rulers being also furnished
with devices to permit of the determination of the length of these lines and the
distances from the principal points in relation to the vertical by the aid of the cord
and weight in order to effect the drawing on the paper all substantially as and for
the purposes herein before described.
2. The new or improved instrument for drawing from Nature or in perspective all
constructed arranged and acting substantially as and for the purposes described and
illustrated with reference to the accompanying drawings.
Dated this 2nd day of January 1895
BREWER & SON,
London and Leeds, Agents for Applicant.