Drawings in Perspective.
Year: 1885

page_text: Drawings in Perspective.
I, ALEXANDER BRIX, at Frankfurt af Main, in the Kingdom of Prussia and
German Empire, Inventor, 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 :—
This apparatus effects a direct preparation of perspectives, without construction,
from the outline and given heights with a single determination of height.
The apparatus distinguishes itself from other arrangements capable only of use
for delineating horizontal figures in that by it not only vertical lines and vertically
placed curves and circles, but also the projection of slanting and curved lines and
the like can be effected by this simple mechanism with considerable saving of time
and great economy of labour.
In the accompanying drawings:
Figure I shews the perspectivograph in outline.
Figure II the same in side aspect.
Figure III the angle of the projection viewed in perspective.
Figure IV a supplementary appliance "vertical circle."
Upon a support, a drawing board for instance G (Figure 1) a right angle composed
of two adjustable slide bars B and B (B B¹ in Figures II and III) is arranged to
travel easily back and forwards on the horizontal support X.
The part B is held by a guide horizontally over the surface of the board, and
consequently the part B is vertical to the same. Upon B¹ slides a holder N carrying
a drawing point K over the paper placed beneath it. A pieco H (Figure III)
sliding on B is connected with N by means of a band S passing round the
roller & so that each motion of H causes a corresponding movement of N. The
band S is kept stretched by a suitable spring Q. The pencil K is also held to
the paper by a suitable spring. Over a given point of the board G is fixed by
means of a clamp W a graduated vertical staff E (Figures II and I) on whose lower
end a movable hollow cylinder F is attached another hollow cylinder C also capable
of being rotated around the vertical staff is attached close to the knee of the
angle B Band through both cylinders a polished rod J passes-whose front end A Z
(Figure II) is bent at a right angle and provided with a style A. If this style A is
drawn in any direction over G, the bars B¹ whilst remaining perfectly parallel to
each other must move correspondingly along X whereby the rod J according to
the guiding of the style slides in and out through the cylinders Cand F. A second
rod J passes through the cylinders L and M which are fixed on the slide H

page_text: immovably, and upon rod E by means of adjustable slides V, upright so that they
are free to turn horizontally and vertically. The front end of the bar J¹ can be
fixed by means of a slide D at any desired height of the scale z and holds the
style AZ vertically because the cylinders G, F, L and M cannot be moved sideways
singly. If now the slide D or the slide V be raised or lowered, or the style be
approached to or removed from the bars B the rod J' must correspondingly lift or
depress the slide H, that is, by means of slide H adjust the slide N and move the
pencil K upon B¹.
MODE OF USING THE APPARATUS.
The outline is secured under the style A in the required position with regard to
the point of view which latter is determined by adjustment of the scale E. The
position of the eye otherwise the required height of the horizon is fixed by securing
the slide V upon the scale E. The style is then carried over the outlines, whereon
according to the adjustment of the slide D, the figures in question are reproduced
either as on the same level or at a given height above the same in perspective.
Vertical lines are drawn by simply raising or lowering the slide D over the corre-
sponding portions of the outline. In the delineation of vertical circles the slide D
is simply carried in the curve required over the projected centre, for which purpose
the graduated apparatus shewn in Figure IV is employed. A foot plate a supports
a perpendicular graduated column 6 on which an arm d capable of motion in a
vertical plane can be adjusted at any given height the radius of the circle to be
described is fixed by means of a slide e to which a little fork fis so fixed that it can
rotate. The apparatus is placed with the edge y of the foot plate a upon the
projection line of the curve on the outline, the rod A Z of the principal apparatus
passed through the fork f, the slide D placed on same from above, with loosened
clamp screw, and the arm & turned on its axis: the pencil K will then describe the
required curve in the perspective. With minus elevations (centre of a bridge arch,
cellar stairs or the like) the graduations E and Z are read taking a higher division
as zero, above this the eye point determined at the requisite height the connecting
band & lengthened correspondingly, and the requisite divisions over or under the
assumed zero counted off on %.
The rest of the drawing proceeds as already described.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is
The combination of parts forming the apparatus for delineating pictures in
perspective, without construction, from given outlines and given heights with single
determination of heights, consisting essentially of a drawing board with guides X
and P for the rectangle B B¹, the slides H and N and connecting arrangement S 8
the cylinders C, F, L, and M. the rods J¹ and Z, A, J, style A, vertical scale E
slides V and D screw clamp arrangement W divisions Z and E, pencil K with spring
pressure tension spring Q and vertical circle describing apparatus, substantially as
described.
WP. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.