Improvements in Slide Rules and other Calculators.
Year: 1892

page_text: Date of Application, 20th Sept., 1892
Complete Specification Left, 20th June, 1893-Accepted, 5th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in Slide Rules and other Calculators.
I, WILLIAM TOM GOOLD, Engineer, of 18 The Hawthorns, Finchley, in the
County of Middlesex, do hereby declare the nature of this invention to be as
follows:-
This invention has for its object the adaptation of the slide rule or any other
known calculator for the purpose of mechanically producing or showing results
when such results are based upon formulæ and are not positive and certain.
To this end I employ one or more movable pointers, arrows or indicators, working
in a slot or slots or otherwise, on any convenient part of the slide rule or calculator,
in such position that any pointer may be fixed against any one of a number of
standard marks, each of which corresponds to a given formula, so that when the
rule or indicator is actuated in the ordinary way by shifting one part of same in
relation to another, the instrument will indicate the result required as calculated
according to the particular formula to which the pointer or pointers has or have
been set.
The invention is generally applicable to all purposes where it is necessary to be
able to calculate readily and with certainty definite results according to any given
formula, such as for belting transmission, electrical or engineering problems,
etc., etc.
Dated this 20th day of Sentember 1892
ALLISON BROS.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Slide Rules and other Calculators.
I, WILLIAM TOм GOOLD, Engineer, of 18 The Hawthorns, Finchley, in the
County of Middlesex, 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 adaptation of the slide rule or any other
known calculator for the purpose of mechanically producing or showing results
when such results are based upon formule and are not positive and certain.
To this end I employ one or more movable pointers, arrows or indicators, working
in a slot or slots or otherwise, on any convenient part of the slide rule or calculator,
in such position that any pointer may be fixed against any one of a number of
standard marks, each of which corresponds to a given formula, so that when the
rule or indicator is actuated in the ordinary way by shifting one part of same in
relation to another, the instrument will indicate the result required as calculated
according to the particular formula to which the pointer or pointers has or have
been set.
The invention is generally applicable to all purposes where it is necessary to be
able to calculate readily and with certainty definite results according to any given
formula, such as for belting transmission, electrical or engineering problems,
etc., etc.
The accompanying drawing shows a suitable manner of carrying the invention
into effect.
In such drawing A is the movable pointer or indicator which works in a slot in
the slide B of the rule, and the end a of which is set to a mark on such slide such

page_text: as b, b', each corresponding with any desired formula. The indicator A is shifted
to any desired formula and then moves with the slide B and indicates the desired
result on scale C of the rule according to such formula.
It will be readily understood that the movable pointer A might be mounted on
the rule itself (instead of on the slide), in which case such rule would carry the
marks indicating different formulæ to which such pointer is to be set, while the
slide B would bear the scale for indicating the result.
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 :-
The improvement in slide rules and other calculators, in which a movable
pointer or pointers is or are mounted on one part of same so that it or they can be
set to any desired formula, whereby the calculator when actuated in the ordinary
way will indicate results according to the special formula to which the pointer has
been set, substantially as specified.
Dated this 20th day of June 1893
ALLISON BROS.,
Agents for the Applicant.