A New and Improved Slide Rule for Reducing Spirits.
Year: 1896

page_text: Date of Application, 2nd July, 1896
Complete Specification Left, 1st Apr., 1897-Accepted, 15th May, 1897
PROVISIONAL SPECIFICATION:
A New and Improved Slide Rule for Reducing Spirits.
I, MATTHEW JOSEPH SHERIDAN, Gentleman, 20 Heathland Road Stoke
Newington London, N. do hereby declare the nature of this invention to be as
follows:-
A slide rule for use in the operations of reducing the strengths of spirits by the
addition of water-the marked indications of quantities on which rule are based on
the unchangeability of the combined weights of alcohol and water, and allow for
the contraction in bulk which takes places when water is added to spirits.
This slide rule will be constructed to show the water required to reduce spirits of
any degree of strength from 70 overproof to 40 underproof, the quantities so shown
on the rule allowing for the contraction in bulk which takes place in the combined
bulk. This allowance for contraction is the special or novel feature of the invention.
The rule will be made up of three parts, viz. the slide rule and two rules which will
form a frame-work in which the slide rule will move so as to indicate the strengths
and quantities necessary to show the results required.
Dated this 22nd day of July 1896.
M. J. SHERIDAN.
I, MATTHEW JOSEPH SHERIDAN 71 Eastcheap, London E.C. Publisher 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:-
The invention consists of a slide rule specially constructed, lined and marked to
enable to be ascertained the correct quantity of water required to reduce spirits
from higher to lower strengths, having regard to the contraction in volume which
results from the addition of water to spirits.
The figures and marking on the rule are based on the weights of admixtures of
alcohol and water, this basis affording the only correct means of estimating the
quantity of water required to reduce.
The slide rules at present in use are not based on weight but on bulk, and failing
to take any account of contraction give results which are incorrect and misleading.
Thus if it be required to reduce 90 gallons of spirit from a strength of 40 degrees
overproof to a strength of 25 degrees underproof these rules would show the
aggregate volume of spirit and water to be 168 gallons, equivalent to an addition.
of 78 gallons of water to the 90 gallons of spirit, as the quantity necessary to reduce
to a strength of 25 underproof.
In this admixture, however, the resultant strength would not be 25 underproof
but about 23 underproof, and to arrive at the required strength of 25 underproof

page_text: further additions of water would have to be made until, by the aid of the
hydrometer, testing the strength after each such addition, the nearest approach
to 25 underproof is obtained.
My invention remedies this defect in existing rules and enables the correct
strength to be obtained in one operation of adding water.
Thus in the foregoing example the aggregate volume of spirit and water would
be shown to be 171 gallons, as nearly as possible, equivalent to an addition of
81 gallons of water to the 90 gallons of spirit.
This addition of water is 33 gallons in excess of the quantity ascertained by the
present rules, and such excess is necessary to ensure the desired strength of
25 degrees underproof. Similarly in larger or smaller operations the quantities
indicated by my invention will be greater than those shown by the existing rules
in proportion to the rate of contraction in volume which takes place in the various
mixtures of spirit and water in reducing operations.
As illustrative of this difference I beg a reference to the example of a reducing
operation shown in the accompanying drawings.
The rule section marked A is my invention.
The rule section marked B is the present rule.
The example shown in the setting of 40 overproof (A.) on the slide (right of
"proof" is overproof, and left of "proof" is underproof) to 90 gallons, gives
171 gallons over 25 underproof.
Similar setting of 40 overproof on "B" gives 168 gallons over 25 underproof.
Thus in this example a difference of 3 gallons is shown in the aggregate volume
of spirit and water, and as the 90 gallons of spirit is common to both this difference
of 3 gallons must be made up in the greater quantity of water required to be
added such being the quantity corresponding to the contraction in volume in
the mixture of 'these particular proportions of spirit and water. Similarly the
indications of the rules would differ at every other proportionate mixture.
=140°; 25 underproof
-
75°)
90 x 140
75
=168 gallons.
The theory on which the present rules are based is simply that the difference
in bulk between the spirit before reducing and that after reducing and contraction
represents the quantity of water required, and the theoretical rule to ascertain
this is Multiply the bulk of spirit to be reduced by its degrees of proof strength
and divide product by degrees of proof in strength required. Thus, in the example
shown (40 overproof
(See rule B.) (This is simply bulk after reducing & contraction.)
The theory on which my invention is based combines the bulk with the weight or
specific gravity of the spirits, and by so doing provides for the contraction in volume.
The rule is Multiply the bulk of spirits before reducing by its then specific
gravity and multiply the bulk after reducing and contraction by its specific gravity
and the difference in the products will be the quantity of water required to he
added to the original bulk of the spirit to ensure the required strength. This
addition is shown on rule A. Thus for example:-
Spirit of 40 overproof is taken to be of a specific gravity of 8631 at 62° F. or
of 8641 at 60° F.
Spirit of 25 underproof is taken to be of a specific gravity of 9464 at 62 F. or
of 9474 at 60.F.
=. 40.0.p.
90 gallons bulk of spirit before reducing
168 gallons bulk after reducing and contraction =.25 u.p.
Ex.: (168 x sp. gr. of 25 u.p. spirit) (90 x sp. gr. of 40 v.p.) = 81.3 gallons.
81.3 +90= 171-3 combined volume.
-
It will therefore be seen that the difference of 3.3 gallons (171-3
168) shown
in these calculations is shown on the rules A & B in drawings-such difference
representing the amount of contraction in the mixture, and corresponding to the
quantity of water in excess of that shown by present rules, necessary to ensure
correct strength as required.

page_text: As the rate of contraction in bulk varies with the range of spirit strengths before
and after reducing, so the graduations on my rule are made to vary correspondingly
throughout.
The invention will be of the ordinary slide rule pattern, with one or more slides,
the lines and indications being logarithmetically laid down, and the quantities and
strengths being shown in gallons and degrees or fractions of gallons and degrees
according to the lengths in which the rules are made.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
A slide-rule for reducing spirit of construction as herein described and
illustrated.
M. J. SHERIDAN.