IMPROVEMENTS IN THE CONSTRUCTION OF PHOTOGRAPHIC STUDIOS
Year: 1875

page_text: LETTERS PATENT to Robert Slingsby, of the Town and County of
Lincoln, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OF PHOTOGRAPHIC STUDIOS."
Sealed the 14th March 1876, and dated the 24th September 1875.
PROVISIONAL SPECIFICATION left by the said Robert Slingsby at
the Office of the Commissioners of Patents, with his Petition, on
the 24th September 1875.
I, ROBERT SLINGSBY, of the Town and County of Lincoln, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF Photographic StuDIOS,” to be as follows :-
My Invention consists in constructing the "sky light" as well as the
"side light" of a photographic studio with a double pitch or inclination
inwards to the middle of its length, where the two inclined or sloping
surfaces meet at about an angle of 120 degrees. The "sky light" and
"side light" are thus virtually divided in their length at this inwardly
projecting angle into two halves, through either of which a greater

page_text: amount of light is admitted from one direction to the adjacent end of
the studio than through a sky light and side light of the ordinary straight
construction of nearly double the length, the light passing in an
unbroken direction towards the sitter through the whole of the nearest
half of the sky light and side light.
By reason of the double inward pitch or inclination of the sky light
and side light the above-mentioned advantage is secured at whichever
end of the studio the sitter may be placed, both ends of the studio being
lighted equally well. The position of the two portions of the side light
and sky light relatively to the sitter is such that the portion of the
side light and sky light which illuminates the opposite end of the studio
is edgewise towards the sitter, and therefore not visible to him. The
whole of the glass through which the light reaches the sitter being at
almost the same distance from and altogether near to the sitter, the
time required for exposure will be shortened considerably.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Slingsby in the Great Seal Patent Office
on the 23rd March 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
SLINGSBY, of the Town and County of Lincoln, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Lettors Patent, bearing date the Twenty-fourth day of September, in the
year of our Lord One thousand eight hundred and seventy-five, in
the thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Robert Slingsby, Her special
licence, that I, the said Robert Slingsby, my executors, administrators,
and assigns, or such others as I, the said Robert Slingsby, my exe-
cutors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN THE CONSTRUCTION OF PHOTOGRAPHIC STUDIOS," upon the con-
dition (amongst others) that I, the said Robert Slingsby, my executors

page_text: or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Robert Slingsby, do hereby declaro
the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in
and by the following statement, reference being had to the accom-
panying Sheet of Drawings, and to the letters and figures marked
thereon, that is to say :-
My Invention consists in constructing the "sky light" as well as the
"side light" of a photographic studio with a double pitch or inclination
inwards from the two ends to the middle of its length, where the two
inclined or sloping surfaces meet at an angle of about 120 degrees. The
"sky light” and “side light" are thus virtually divided in their length
at this inwardly projecting angle into two halves, through either of
which a greater amount of light is admitted from one direction to the
adjacent end of the studio than through a sky light and side light of the
ordinary straight construction of nearly double the length, the light
passing in an unbroken direction towards the sitter through the whole
of the nearest half of the sky light and side light.
By reason of the double inward pitch or inclination of the sky light
and side light, the above-mentioned advantage is secured at whichever
ond of the studio the sitter may be placed, both ends of the studio
being lighted equally well. The position of the two portions of the
side light and sky light relatively to the sitter is such that the portion
of the side light and sky light which illuminates the opposite end of the
studio is edgewise towards the sitter, and therefore not visible to him.
The whole of the glass, through which the light reaches the sitter, being
at almost the same distance from and altogether nearer to the sitter, the
time requirod for exposure will bo shortened considerably.

page_text: The sky light, instead of being straight or in a single plane sloping
downwards from the top to the caves of the roof as usual, is constructed
with a slope of about 30 or 40 degrees inwards or downwards from each
end to the middle of its length, besides sloping downwards to the eaves
of the roof. The sky light is thus composed of two similar parts or
halves a, a', which are sloped or inclined as above described, and meet
at 6 at an angle of about 120 degrees to one another. The side light is
also composed of two parts c, c', of equal length, which are inclined
inward and meet at d, and stand at an angle of about 120 degrees to
one another.
The lowest and highest points of the sky light at the middle of the
studio should be respectively about 6 feet and 10 feet from the floor of
tho studio. The sitter is lighted by the nearest halves only of the sky
and side lights, which face towards him, the other halves which face tho
other way being radial to the sitter, and therefore invisible to him, and :
are used only when the position of the sitter is changed to the opposite
end of the studio.
Instead of the sky and side lights meeting at an angle at 6 and d as
above mentioned, they may be separated a few feet by an unglazed or
darkened portion of straight roof and side, under which the camera may
be placed in comparative obscurity.
By means of this double inward pitch of the sky and side lights the
studio is lighted equally well at either end, a greater amount of light
being admitted in the direction of the sitter through either half of a
sky and side light, having a total length of 10 feet constructed according
to my Invention than through a light of the ordinary straight construc.
tion 20 feet in length.
The arrangement and construction of the frames and sashes will bo
evident from the Drawings and readily understood without description,
and moreover may be varied according to circumstances.
Instead of the side light being vertical it may be sloped outward
from top to bottom, the sky light being at one slope and the side light
at another slope, or they may both be at the same slope and combined in
one in the form of what is known as a "Mansard" roof, but with the
double pitch or inclination inwards at the contre, as will be readily
understood.

page_text: "
I have represented and described the sky and side lights with a double
inward pitch or inclination in order that the sitter may be placed at
either end of the studio as above mentioned, but it will be obvious that
this inward pitch or inclination of the sky and side lights may be
adapted in a single form to studios in which the sittings are made at one
end only.
Having described the nature of my said Invention, and the manner of
performing the same, I declare that what I claim as the Invention to be
protected by the herein-before in part recited Letters Patent is,-
1st. Constructing both the sky light and the adjacent side light of a
photographic studio with a double pitch or inclination inwards towards
the centre (in addition to the ordinary inclination of the sky light down-
wards towards the eaves), substantially as and for the purpose shown
and described.
2nd. The modifications in the construction of the sky light and side
light herein specified.
3rd. The application of one-half of the sky light and side light con-
structed as herein set forth, to a studio in which the sitter is always
placed at the same end, substantially as specified.
In witness whereof, I, the said Robert Slingsby, have hereunto set
my hand and seal, this Twenty-third day of March, in the year of
our Lord One thousand eight hundred and seventy-six.
ROBERT SLINSCRY 1.01