AN IMPROVED APPARATUS FOR AND METHOD OF ASCERTAINING THE STATE OF SEWERS, TUNNELS, DRIFTS, OR OTHER SUBTERRANEAN WORKS WITHOUT DESCENDING THEREINTO BY MEANS OF THE NATURAL, ARTIFICIAL OR MAGNESIUM LIGHT, PART OF WHICH APPARATUS IS APPLICABLE TO LEVELLING PURPOSES
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by Richard William Barnes at the
Office of the Commissioners of Patents, with his Petition, on the 25th
September 1865.
I, RICHARD WILLIAM BARNES, of the City of Manchester, in the County
of Lancaster, Civil Engineer, do hereby declare the nature of the said Inven-
tion for "AN IMPROVED APPARATUS FOR AND METHOD OF ASCERTAINING THE STATE
OF SEWERS, TUNNELS, DRIFTS, OR OTHER SUBTERRANEAN WORKS WITHOUT DESCENDING
THEREINTO BY MEANS OF THE NATURAL, ARTIFICIAL OR MAGNESIUM LIGHT, PART OF
WHICH APPARATUS IS APPLICABLE TO LEVELLING PURPOSES," to be as follows:-
This Invention has for its main object the examination or the ascertaining
of the state of sewers, tunnels, drifts, and other subterraneous work without
the person who is conducting the inspection having to be in close proximity
to or in the immediate vicinity of such work, and consists, firstly, in the use
and application of a lantern which is constructed with an outer and inner
casing, so that the space between the said casings forms one or more chambers
or passages for the requisite amount of air to support the flame of the lamp,
and which quantity of air is supplied through the top part or roof of the
lantern in order that when necessary the said lantern may be sunk in water
until the flame of the lamp is on a level with or below the surface o the
water. A cavity of a triangular, rectangular, polygonal, or other suitable
shape is formed between the outer and inner casings of the lantern, tlie ends'

page_text: of which cavity are open for the purpose of enabling a staff or rod (herein-
after described) to be passed through; or an equivalent for the said cavity
may be constructed on the outside of the lantern for the same purpose; and
such lantern may or may not be provided with a reflector.
The second part of this Invention relates to what may be called the re-
flecting apparatus, which consists of a suitable framework provided with a
similar shaped cavity to the one in the lantern herein-before described, which
is also for the purpose of enabling a staff or rod (herein-after described) to
be passed therethrough, in which framework a reflector (made of metal or
any other suitable material, is mounted and so arranged as to be adjustable
to any required angle upon its own axis by means of a tangent screw or other
suitable means.
Thirdly, this Invention consists of a staff or rod made of metal, wood, or of
any other suitable material, and which, for the sake of portability, it is
preferred to hinge together in parts, so that it may be doubled up into
a portable form, and to ensure rigidity when opened out to its full length,
internal bolts, the handles of which are flush with the outer surface of the
staff or rod, may, be inserted longitudinally at the end of every one of such
parts, so that, when such bolts are pushed, out or locked they will effectually
and rigidly lock and fasten the parts together in a straight line; it is also
advisable to graduate or mark divisions upon the said staff or rod. It will
be readily understood that such a staff or rod is equally applicable as a level-
ling staff, but to be used in conjunction with the lantern and reflecting appa-
ratus herein-before described it is necessary to have the said staff or rod
formed externally of the same shape and size as the cavity in or its equivalent
on the outside of the lantern, or on the reflecting apparatus, in order that
when passed through such cavities the lantern or reflecting apparatus respec-
tively may be moved along or have their positions altered upon the said
staff or rod by means of a graduated band, cord, chain, or pliable metal wire
attached to the lantern or reflecting apparatus and fastened to the staff or
rod in any desired position, so that by means of the graduations or division
marked upon such staff, rod, band, cord, chain, or wire, the lantern or reflect-
ing apparatus respectively may be regulated to the greatest niecety. When
so arranged the said staff or rod is intended to be used as a guide for direct
ing the rays of light from the lantern in any required direction to the reflecting
apparatus, which is also mounted upon an exactly similar staff or rod.
Fourthly, this Invention consists in the application of the natural or
ordinary daylight in conjunction with the reflecting apparatus herein-before
described, and also consists in the use and application of the "magnesium,"

page_text: light (burnt either in the open air or in the lantern herein-before specified)
in conjunction with the reflecting apparatus herein-before described. It will
be readily apparent that if such a lantern or light is applied to one part of
a sewer (for instance) the rays of light proceeding from such lantern or light
may be reflected from the reflecting apparatus situated at another point of
the sewer in any required direction, provided that no obstacle intervenes, and
by means of such apparatus the state of sewers, tunnels, drifts, or other sub-
terranean work may be examined without the person conducting the inspec-
tion having to descend down into such subterranean works, or without his
having to be in close proximity to such works.