AN IMPROVED INSTRUMENT FOR ASCERTAINING THE SPECIFIC GRAVITY OF LIQUIDS
Year: 1862

page_text: LETTERS PATENT to William Moir, of the City of Manchester, Gen-
tleman, for the Invention of "AN IMPROVED INSTRUMENT FOR ASCERTAINING
THE SPECIFIC GRAVITY OF LIQUIDS."
Sealed the 17th October 1862, and dated the 23rd April 1862.
PROVISIONAL SPECIFICATION left by the said William Moir at the
Office of the Commissioners of Patents, with his Petition, on the 23rd.
April 1862.
I, WILLIAM MOIR, of the City of Manchester, Gentleman,. do hereby
declare the nature of the said Invention for "AN IMPROVED INSTRUMENT FOR..
ASCERTAINING THE SPECIFIC GRAVITY OF LIQUIDS," to be as follows:-
This instrument is based upon the law of hydrostatics that when two.
columns of dissimilar liquids are made to communicate by means of a lateral
tube the vertical heights of the two columns are precisely the inverse of their
densities. If, therefore, the specific gravity of any fluid is to be determined
by this instrument, a partial vacuum is produced by pressing the air out of an
elastic ball or otherwise with which two tubes are in communication, then:
turn a stop-cock to exclude the air so expelled, then insert the left-hand tube.
into distilled water to about one quarter inch above the first engraved mark upon
the tubes, and the other or right-hand tube into the liquid to be investigated,.
then slowly and with care turn the tap till the fluids in both tubes rise,, stop.

page_text: the instant that the distilled water has reached 100° on the scale, and the
other liquid will stand at whatever degree its specific gravity may be as com-
pared to distilled water; thus if the liquid to be tested be sulphuric acid,
the height of the column will indicate its real density as 1.50, or 1.55, or 1.60,
as the case may be. On the contrary, if the liquid to be tested is lighter
than water, as alcohol, the operator must allow the lighter fluid in the right-
hand tube to rise to zero on the scale, and its' specific gravity will be found at
the degree indicated by the distilled water; thus alcohol, when at 0 in the
right-hand tube, will have its specific gravity indicated by the degree at which
the distilled water stops, and may be read as 0.82, or 0.84, or 0.90, as the
case may be. To expel the fluids from the tubes, compress the elastic ball,
then open the tap, and the fluids will be ejected into the vessels from which
they were raised.
The mean temperature of 60° Fahrenheit being taken as a standard, the
following correction may be necessary in determining the specific gravity of
spirits or wines:-If the temperature of the wine or spirit to be experimented
on is upwards of 60°, add 3. to the third decimal place for every 5° of tem-
perature over 60°. If the temperature is below 60°, deduct 3 from the third
<decimal place for every 5 degrees under, but for general purposes this cor-
rection is not material..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Moir in the Great Seal Patent Office on the
22nd October 1862.
i
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MOIR, of the City of Manchester, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of April, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Moir, Her special license that I, the said William.
Moir, my executors, administrators, and assigns, or such others as I, the
said William Moir, 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 Invention for "AN.

page_text: IMPROVED INSTRUMENT FOR ASCERTAINING THE SPECIFIC GRAVITY OF LIQUIDS," upon
the condition (amongst others) that I, the said William Moir, 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 months next and immediately after the date of the said Letters
Patent..
NOW KNOW YE, that I, the said William Moir, do hereby declare
the nature of my said Invention, and in what manner the same is to be per
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
This instrument, consisting of two tubes in communication with an exhaust,
ing apparatus, and which I call the vacua hydrostatic balance," is based
upon the well-known law of hydrostatics that when two columns of dissimilar
liquids are made to communicate by means.. of a lateral tube the vertical
height of the two columns are precisely the inverse of their densities.
In order that my Invention may be fully understood; and readily carried
into operation, I will proceed to describe the accompanying Drawing, in
which A represents an elastic ball for exhausting the air in the tubes D and E,
which are in communication with each other by the lateral or curved tube C,
provided with a stop-cock B.
In order to determine the specific gravity of any liquid by this instrument,
a partial vacuum is produced by pressing the air out of the elastic ball A;
turn the stop-cock B to exclude the air so expelled; then insert the left-hand
tube D into distilled water to about half an inch above the lowest engraved
mark upon the tubes, and the other or right-hand tube E into the liquid to be
investigated; then slowly and with care turn the tap B till the liquids in both
tubes rise; stop the instant that the distilled water has reached one hundred
degrees on the scale, and the other liquid will stand at whatever its specific gravity
may be; thus, if the liquid to be tested be sulphuric acid, the height to which it
rises will indicate its real density as 1.50, 1.55, 1-605, as the case may be.
On the contrary, if the liquid to be tested is lighter than water, as alcohol,
the operator must allow the lighter liquid in the right-hand tube to rise to 0
on the scale, and its specific gravity will be found at the point indicated by
the distilled water in the left-hand tube; thus alcohol; when at 0 in the right-
hand tube, will have its specific gravity indicated by the degree at which the
distilled water stops, and may be read as 0.82, 0.84, 0.905, as the case may
be. To expel the liquids from the tubes, compress the ball with the left

page_text: hand, then open the tap, and the liquids will be ejected into the vessels from
which they were raised.
-
Note. The mean temperature of sixty degrees Fahrenheit being taken as a
standard, the following correction for temperature may be found necessary :-
If the temperature of the liquid to be experimented on is upwards of sixty
degrees, add three to the third decimal place for every five degrees of tem-
perature over sixty degrees. If the temperature is below sixty degrees,
deduct three from the third decimal place for every five degrees under. The
division of the scale into half degrees carries the indications to the third
decimal place, as 1:605, 0.105.
Although I have adopted an elastic ball to produce a vacuum, the vacuum
may be produced by an exhausting syringe or by extracting the air from the
tubes by means of the mouth, or by any other mode whereby liquids are raised,
such as by pumping.
Having thus stated the nature of my Invention, and described a convenient
mode of performing the same, I declare that I claim the application and
adaptation of the hydrostatic law for acertaining the specific gravity of liquids,
and the improved instrument shewn and described, or any modification
thereof for carrying the same into effect, also the inversion of the degrees
on the scales.
"In witness whereof, I; the said William Moir, have hereunto set my hand
and seal, this Eighteenth day of October, in the year of our Lord
One thousand eight hundred and sixty-two.
WILLIAM MOIR. (L.B.)