APPENDIX 1. 
TABLES FOR FACILITATING STATISTICAL WORK. 
A. CALCULATING TABLES. 
For heavy arithmetical work an arithmometer 18, of course, 
invaluable ; but, owing to their cost, arithmetic machines are, as a 
rule, beyond the reach of the student. For a great deal of simple 
work, especially work not intended for publication, the student 
will find a slide-rule exceedingly useful : particulars and prices 
will be found in any instrument maker's catalogue. A plain 
25-cm. rule will serve for most ordinary purposes, or if greater 
accuracy is desired, a 50-cm. rule, a Fuller spiral rule, or one of 
Hannyngton-pattern rules (Aston & Mander, London), in which 
the scale is broken up into a number of parallel segments, may be 
preferred. For greater exactness in multiplying or dividing, 
logarithms are almost essential : five-figure tables suffice if answers 
are only desired true to five digits ; if greater accuracy is needed, 
seven-figure tables must be used. It is hardly necessary to cite 
special editions of tables of logarithms here, but attention may 
perhaps be directed to the recently issued eight-figure tables of 
Bauschinger and Peters (W. Engelmann, Leipzig, and Asher & Co., 
London, 1910; vol. i. containing logarithms of all numbers from 
1 to 200,000, price 18s. 6d. net.; vol. ii. containing logs. of 
trigonometric functions). 
If it is desired to avoid logarithms, extended multiplication 
tables are very useful. There are many of these, and four of 
different forms are cited below. Zimmermann’s tables are inex- 
pensive and recommended for the elementary student, Cotsworth’s, 
Crelle’s, or Peters’ tables for more advanced work. Barlow's tables 
are invaluable for calculating standard-deviations of ungrouped 
observations and similar work. 
(1) BARLOW’S Tables of Squares, Cubes, Square-roots, Cube-roots, and Recip- 
rocals of all Integer Numbers up to 10,000; E. & F. N. Spon, 
London and New York; stereotype edition, price 6s, 
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