NEW ELTHAM, LONDON, S.E.9 
359 
FULLY DESCRIPTIVE LEAFLET ON APPLICATION 
Quote Stanley’s 'A' Catalogue 
THE “OTIS KING ” CALCULATOR 
A8921-A8922 
Size fully extended, I0J X IJ in. 
Size closed for pocket, 6 X IJ in. 
The “ Otis King ” Calculator is a pocket size instrument for the use of Scientists, 
Mathematicians, Engineers, Bankers, Accountants, and all business men dealing with 
figures. It affords a simple means of solving rapidly and accurately almost every kind of 
calculation. 
Spiral scales, which are plastic covered, and resistant to wear and moisture, are 
mounted on two tubes, while a third tube, mounted on the Holder, forms a tubular 
cursor, carrying at each end an engraved arrow or pointer which can be set at any mark. 
As all three parts of the instrument are made of metal there is no possibility of warping. 
Three simple movements form the basis of every calculation, and full working instruc 
tions are supplied with the instruments. Two models are available as follows :— 
A892I “ Model K ” Otis-King Calculator, for all calculations involving multiplica 
tion, division and proportion, including costs, percentages and foreign exchange 
problems. Except where reading of logarithms is desired, it is recommended in 
preference to Model L, as the double scale on the cylinder frequently reduces the 
number of settings in a series of calculations. 
A8922 “ Model L ” Otis-King Calculator, for all calculations for which Model K can 
be used. It gives in addition, logarithms of all numbers, by means of which roots 
and powers may be calculated. 
ACCURACY 
Users of the slide rule will realise at once the value of the 66 in. scales of the Otis King’s 
Calculator. Accurate results to four or five significant figures can be relied on.