AN IMPROVED METHOD OF AND INSTRUMENT FOR MEASURING DISTANCES
Year: 1860

page_text: LETTERS PATENT to William Henry Woodhouse, of Parliament Street,
in the City of Westminster, Civil Engineer, for the Invention of "AN
IMPROVED METHOD OF AND INSTRUMENT FOR MEASURING DISTANCES."
Sealed the 10th May 1861, and dated the 16th November 1860.
PROVISIONAL SPECIFICATION left by the said William Henry Wood-.
house at the Office of the Commissioners of Patents, with his Petition,
on the 16th November 1860.
I, WILLIAM HENRY WOODHOUSE, of Parliament Street, in the City of
Westminster, Civil Enginer, do hereby declare the nature of the said Invention
for "AN IMPROVED METHOD OF AND INSTRUMENT FOR MEASURING DISTANCES," to be.
as follows:-
My instrument for measuring distances consists of a tube similar to a
telescope tube, with one fixed and one movable hair, or two movable hairs or
wires, or other fine lines parallel to each other, and similar to the fixed bair in
a spirit level. The hairs are so arranged that the distance between them can
be altered, and I prefer to do this by a screw or screws and rack, some part
of which is graduated or marked like a scale, so that the distance between the
hairs can be ascertained. The instrument may be made with or without
magnifying or telescopic glasses.
The method of determining the distance of any object of which the height or
breadth is known or can be estimated is as follows:-When looking through
the tube adjust the hairs, so that one is in a line between the eye and the top

page_text: of the object, and the other in a line between the eye and the bottom of the
object. Then as the distance between the hairs is to the height of the object,
so is the distance between the eye and the hairs to the distance between tho
hairs and the object.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Henry Woodhouse in the Great Seal Patent Office
on the 16th May 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HENRY WOODHOUSE, of Parliament Street, in the City of Westminster, Civil
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of November, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Henry Woodhouse, Her special licence that I, the said William
Henry Woodhouse, my executors, administrators, and assigns, or such others
as I, the said William Henry Woodhouse, my executors, 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 Inven-
tion for "AN IMPROVED METHOD OF AND INSTRUMENT FOR MEASURING DISTANCES,"
upon the condition (amongst others) that I, the said William Henry
Woodhouse, my executors 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 mouths next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Henry Woodhouse, do hereby
declare 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 thereof, reference being had to the Drawings hereunto
annexed, that is to say :-
My instrument for measuring distances consists of a tube similar to a
telescope tube, with one fixed and one movable hair, or two movable hairs, or

page_text: wires, or other fine lines parallel to each other, and similar to the fixed hair in
a spirit level. The hairs are so arranged that the distance between them can
be altered, and I prefer to do this by a screw or screws and rack, some part of
which is graduated or marked like a scale, so that the distance between the
hairs can be ascertained. The instrument may be made with or without
magnifying or telescopic glasses.
Figures 1 and 2 of the accompanying Drawings are elevations of different
sides of one of my instruments for measuring distances; Figure 3 is an end
view of the same. a is a box or case at the end of the instrument, fitted on
the end of a tube a' inside an outer tube b; the further end of the tube b is
toothed, as shown at e, into the teeth of which a pinion f takes, and is sup-
ported at the side of the box a by a plate g; h is a plate free to slide in dove-
tail grooves formed in the outer end of the box a, and furnished at one side
with a rack, into which the pinion f also takes; i is a fixed hair on the face
of the box a; k is another hair free to move with the plate h; is a graduated
scale at the side of the box a, so arranged that when the movable hair is
exactly over the fixed hair the unit of the scale corresponds with a line drawn
on the side of the plate h. By turning the outer tube b the pinion f com-
municates an up-and-down motion to the plate h, and consequently to the
hair k; m is a stud on the tube a', which works in a slot formed in the tube b,
in order to determine the extent of travel of the plate h, and consequently the
extent of separation of the movable from the fixed hair.
The method of determining the distance of any object of which the height or
breadth is known or can be estimated is as follows:-When looking through
the tube adjust the hairs, so that one is in a line between the eye and the top
of the object, and the other in a line between the eye and the bottom of the
object. Then as the distance between the hairs is to the height of the object,
so is the distance between the eye and the hairs to the distance between the
hairs and the object.
Supposing the length of the tube from the eye-piece to the hairs to be one
yard, and the distance between the hairs 10th of an inch, and the height of
the obiect 70 inches

page_text: manner the same is to be performed, I declare, that I claim the improved
instrument for measuring distances, herein-before described.
In witness whereof, I, the said William Henry Woodhouse, have here-
unto set my hand and seal, this Fourteenth day of May, One thousand
eight hundred and sixty-one.
W. HENRY WOODHOUSE. (L.S.)
W. HENRY WOODHOUSE. (L.S.)