Improvements in Measuring Rods and Stands or Tripods.
Year: 1886

page_text: Date of Application, 7th July, 1886.
Complete Left, 6th Apr., 1887.
Complete Accepted, 13th May, 1887.
Improvements in Measuring Rods and Stands or Tripods.
1, EDWARD CROSSLEY of Bermerside, Halifax in the County of York, Fellow of
the Royal Astronomical Society do hereby declare the nature of my invention for
"IMPROVEMENTS IN MEASURING RODS AND STANDS OR TRIPODS," to be as follows:-
The object of my invention is the construction of an improved measuring rod and
stand or tripod by means of which I am able to obtain very accurate results with a
considerable saving of time and labour.
My improved measuring rod and stand or tripod onable me to measure any required
distance over uneven ground with an accuracy hitherto unattainable by any but the most
elaborate methods.
My apparatus is inexpensive light and easily manipulated.
In order to carry out my invention I construct the bearings at each extremity of the
measuring rod of brass or other suitable material in the form of spherical cups.
Upon the top of the stand or tripod is secured a ring or flat plate of brass or other
suitable material with a circular aperture. Upon this ring or plate a short pedestal of
brass or other suitable material with a flat base slides freely and is surmounted by a
spherical head of the same radius as the cups at the extremities of the rod.
The pedestal slides freely upon the upper surface of the ring or plate in any direction
thus enabling the operator to bring the spherical head easily into any position which
may be required in order to place the spherical cup at the extremity of the rod upon it
and to adjust the rod in any required direction, when the pedestal can be clamped by
a suitable clamping arrangement.

page_text: The measuring rod is fitted with thermometers and a clinometer as usual. In order
the more readily to test the length of the measuring rod I make use of a standard rod
which I construct with a spherical cup of brass or other suitable material at one of its
extremities the cup being equal in radius to the spherical heads on the pedestals of the
stands or tripods. At the other extremity of the standard rod I construct a V shaped
groove or a cylindrical groove of the same radius as the spherical heads on the
pedestals. The spherical cup and cylindrical or V shaped groove enable the standard
rod to be placed upon the spherical heads of the stands or tripods (after they have been
set and clamped with the measuring rod upon them) without disturbing them and
their distance apart can be easily and accurately ascertained by contact or end
measurement in the usual way.
COMPLETE SPECIFICATION.
Improvements in Measuring Rods and Stands or Tripods.
I EDWARD CROSSLEY of Bermerside Halifax in the County of York Fellow of the
Royal Astronomical Society 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:-
1
The object of my invention is the construction of an improved measuring rod and
stand or tripod by means of which I am able to obtain very accurate results with a
considerable saving of time and labour.
My improved measuring rod and stand or tripod enable me to measure any required
distance over uneven ground with an accuracy hitherto unattainable by any but the
most elaborate methods.
My apparatus is inexpensive light and easily manipulated.
In order to carry out my invention I construct the bearings at each extremity of the
measuring rod of brass or other suitable material in the form of spherical cups.
Upon the top of the stand or tripod is secured a ring or flat plate of cast-iron or
other suitable material with a circular aperture.

page_text: Upon this ring or plate a short pedestal of brass or other suitable material with a
flat base slides freely and is surmounted by a spherical head of the same radius as the
cups at the extremities of the rod.
The pedestal slides freely upon the upper surface of the ring or plate in any direction
thus enabling the operator to bring the spherical head easily into any position which
may be required in order to place the spherical cup at the extremity of the rod upon it
and to adjust the rod in any required direction, when the pedestal can be clamped by
a suitable clamping arrangement.
The measuring rod is fitted with thermometers and a clinometer as usual.
In order the more readily to test the length of the measuring rod I make use of a
standard rod which I construct with a spherical cup of brass or other suitable material
at one of its extremities, the cup being equal in radius to the spherical heads on the
pedestals of the stands or tripods; at the other extremity of the standard rod I construct
a V shaped groove, or a semi-cylindrical groove of the same radius as the spherical
heads on the pedestals. The spherical cup and semi-cylindrical or V shaped groove
enable the standard rod to be placed upon the spherical heads of the stands or tripods,
(after they have been set and clamped with the measuring rod upon them) without
disturbing them, and their distance apart can be easily and accurately ascertained by
contact or end measurement in the usual way.
The method of using my improved Measuring Rod in the field is as follows:-
The distance to be measured is staked off and a sufficient number of posts set up for
lining. At least three tripods are necessary. One is set up over the first stake by
means of the plumb bob, and the head clamped. A cord or chain 100 feet in length
with tabs every 10 feet is stretched along the line to be measured in order to facilitate
the setting of the tripods.
The second tripod
set up over the first tab, and the third tripod over the second
tab, with their heads unclamped.
The measuring rod is now taken and the cup at one end placed upon the head of the
first tripod. The cup at the other end is gently lowered to the head of the second
tripod which is free to take the position necessary to fit the cup. The rod now rests
upon the heads at each end and when placed in the right direction by the sights and
posts for lining the head on the second tripod is firmly clamped. The inclination
of the rod is now read off by the clinometer and the thermometers recorded.
The rod is then lifted off and placed upon the second and third tripods in a precisely
similar manner.
The first tripod is now taken up and set forward over the third tab
and so on to the end of the distance to be measured. The cord or chain being set
forward every 100 feet.
If the rings on the terminal tripods are not horizontal, the inclination of the ring in
the direction of the line must be taken and an allowance made for the position of the
head plus or minus as the case may be.
An accuracy of measurement of 1 in 100,000 is thus easily obtained.
In order to enable my invention to be fully understood, I will now proceed to describe
it by reference to the accompanying drawings.
Fig. I is a general view of the Measuring Rod and Tripods. The Measuring Rod
is in this case constructed in the form of a wooden box A. B, 10 feet long containing a
steel rod C, D, resting on rollers G and firmly attached to metal plates F at each end,
in which the spherical cups E are ground as shewn in section in Fig. II the metal plate
at one end is fixed to the box and the metal plate at the other end is free to move
longitudinally with the expansion and contraction of the steel rod C. D.
Fig. 11 shews one end of the box A. B, the steel rod C. D, the metal plate F with
spherical cup E, the top of the tripod with spherical head H, a cone J attached to the
box to facilitate the placing of the cup E on the spherical head H.
The Measuring Rod is constructed with sights at each end, a clinometer in the
centre, and thermometers between attached to the steel rod.
At K is shewn a sliding piece for measuring any part lengths by means of lines
drawn upon the box, and a plumb bob suspended from the hook L below.

page_text: Fig. III is a plan of the top of the tripod shewing tribrach arm N for clamping,
which is effected by means of the milled headed screw M shewn in Fig. II.
Fig. IV is a general side elevation of comparing bench O P with a 10 feet standard
measuring rod resting upon the spherical heads at each end.
Fig. V is a sectional view showing the position of the heads at each end of the
comparing bench and the construction of the standard rod.
It consists in this case of a steel tube supported at two points in a mahogany box.
The box has a bracket of metal at each end, the one to the right with a spherical cup,
the other with a semi-cylindrical groove.
One end of the tube is telescopic and by means of a scale and vernier the length of
the rod can be read off to less than the thousandth of an inch when the two ends are in
contact with the spherical heads.
The diameter of the heads being known the total length from centre to centre of
each head is determined.
Having now particularly described and ascertained the nature of my said Invention,
and in what manner the same is to be performed, I declare that what I claim is :-
1st. The construction of an improved measuring rod with spherical cups at its
extremities in the manner and for the purpose herein-before described.
2nd. The construction of an improved tripod substantially in the manner herein-
before described with movable pedestals carrying spherical heads, the said pedestals
moving freely on the upper surface of a ring or plate in any direction and capable of
being firmly clamped.
3rd. The construction of a standard measuring rod with a spherical cup at one
extremity and a ▼ shaped or semi-cylindrical groove at the other substantially in the
manner and for the purpose above described.
4th. The improved method hereinbefore described of measuring distances by the
employment of a measuring rod and tripods constructed and operated substantially as
hereinbefore described.