Improved Apparatus for Indicating Variations in the Quantity of Gas, Air or other Fluid Contained in a Test Holder.
Year: 1898

page_text: Date of Application, 31st Dec., 1898-Accepted 18th Feb., 1899
Improved Apparatus for Indicating Variations in the Quantity of
Gas, Air or other Fluid Contained in a Test Holder.
We, JAMES MIINF, Milton House Works, Abbeyhill, Edinburgh, Engineer,
and HENRY O'CONNOR, Milton House Works, Abbeyhill, Edinburgh, Civil
Engineer, 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..
This invention has for its object the provision of means to facilitate the ascer-
taining of the variations in height of the bell of the test holder to a fiuer degree
than is attainable by the methods presently in use.
In test holders there 18 ordinarily attached to the side of the bell a graduated
scale, so divided as to represent cubic feet and tenth and hundredth parts thereof,
in such a manner that any use or fall of the bell is indicated on the scale by
its position relative to the edge of tank or to a pointer fixed thereon, and in
order to aid in the reading of the scale, it has been customary to fix a magnifying
glass upon the top edge of the tank, but difficulty is notwithstanding experienced
in reading the scale to a finci degree than one-hundredth parts of one cubic foot
The present invention consists in attaching to the upper edge of the tank a short
graduated scale fixed in such a manuri that its giaduated edge indicates upon
the ordinary scale on the bell The upper edge of the short graduated scale
takes the place of the pointer above refered to, thus indicating in the usual
manner the tenth and hundredth parts of a fort In order, however, to obtain
a more minute reading, viz, to one thousandth part of one cubic foot, the gradua-
tions of the short scale nie so aanged that 10 of its divisions are equal to 11 of
those on the scale on bell, and each of the former divisions therefore equals
elven thousandths of a cubic foot Consequently, if the upper edge of the short
scale is between any two of the one-hundredth divisions of the larger scale, the
exact number of thousandths by which the lesser of the two divisions of the
large scale is exceeded can be ascertained by noting the particular line on
smaller scale, which coincides, or most nearly coincides, with any line on the
larger scale, and counting the number of divisions between it and the top
In the accompanying sketch the scales are shewn as indicating 217 thousandths
of a cubic foot The tenths and hundredths are read in the ordinary fashion by
noting the position of the upper edge of the short scale A B upon the larger
scale CD Then as the upper edge AB is somewhat above the line indicating
21 hundredth parts, it is desired to know the amount of the excess in one-
thousandth parts. It will be seen that the line on the shorter scale, which
coincides with one of those on the larger marks the seventh division from the
top of the shorter scale, consequently the distance from the top equals 77
thousandths of a cubic foot, while the distance from the coincident line on the
larger scale to the line indicating the 21 hundredth parts equals 70 thousandths of
a cubic foot The difference, equal to 7 thousandths of a cubic foot, represents
the excess of height above referred to.

page_text: Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is
11
Firstly: In test holders for measuring quantities of an, gas or other fluids,
the attaching of a short scale, graduated as above described, by means of which
the upward and downward travel of the hell can be measured to a greater degree
of minuteness than is otherwise obtainable. all as and for the purposes herein-
before set forth, and as illustrated by the annexed drawing
Secondly: Our heicinabove described apparatus applicable to test holders for
measuring quantities of air, gas and other fluids, all as described in the foregoing 1
specification and illustrated by the acompanying drawings
Dated this Thirtieth day of December 1898
JAMES MILNE
HENRY O'CONNOR