IMPROVEMENTS IN INSTRUMENTS OR APPARATUS FOR PRODUCING PICTURES OF BODIES APPARENTLY IN MOTION OR OF CHANGING COLOURS, WHICH PICTURES MAY EITHER BE VIEWED BY DIRECT VISION OR BE EXHIBITED BY THE MAGIC LANTERN
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by Thomas Ross, at the Office of
the Commissioners of Patents, with his Petition, on the 10th October
1871.
I, THOMAS Ross, the younger, of No. 36, Renfield Street, Glasgow, in
the County of Lanark, North Britain, Photographer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN INSTRUMENTS OR
APPARATUS FOR PRODUCING PICTURES OF BODIES APPARENTLY IN MOTION OR OF
CHANGING COLOURS, WHICH PICTURES MAY EITHER BE VIEWED BY DIRECT VISION OR
BE EXHIBITED BY THE MAGIC LANTERN,” to be as follows :-
My Invention consists of the improvements heroin-after described for

page_text: of a man in the act of jumping:-I take two disks, one of glass upon
which said glass disk the figures to be represented are painted, photo-
graphed, or otherwise produced upon the said glass disk. The figures
are represented in a series of gradual or progressive forms and positions
representing the several positions and forms which a man passes through
in the act of jumping. This progression may be effected by any number
of figures, which are arranged in circles round the disk. I will suppose
a subject having thirteen figures in the arrangement. In front of the
said glass disk is the other disk (which may be of metal or other opaque
substance, or of glass made opaque by painting), the said second or
opaque disk having a slot or opening cut out or left out in the propor-
tion of one-thirteenth part of the entire opaque surface or one-fourteenth
of the area of the disk. The said slot or opening is included between
two radii. Both disk ‘rotate on the same axis and are driven by means
of a winch which is connected with two driving wheels, the latter giving
motion to the two disks by means of bands connecting the driving
wheels with a small fixed wheel or pulley at the centre of each disk..
The disks may be made to rotate either in the same or in opposite
directions; the relative speed of the two disks being (for. a thirteen
figure subject) thirteen rotations of the opaque disk to one of the
transparent disk; this difference of speed is obtained by the driving
wheels being as thirteen to ono in their circumference. . The effect
produced by the rapid motion of the opaque disk upon the slowly.
moving disk carrying the figures is the apparent motion of the figure.
Where the number of figures is different from that described the
relative speed of the two disks is varied in like proportion, the opaque
disk making as many rotations to one of the transparent disk as there
are figures in the circle on the transparent disk. The opening of the
opaque disk remains the same, the difference of speed being obtained by
the different proportion of the driving wheels.
Very beautiful effects of gradual change of color are produced by
substituting on the transparent disk circular bands of color in place
of the figures described. For example, if the three primary colors be
arranged in bands concentric with the centre of the glass disk, each one-
third of the disk having the bands differently arranged, the effect of the
rotation will be to produce a gradual dissolving of the colors one into

page_text: the other. As new colors are uncovered by the quicker motion of the
opaque disk, the changing colors may be made to give very curious
effects in the magic lantern, for example, in conjunction with the figure
of a chameleon.