GRAPHICAL AND MECHANICAL AIDS TO 
CALCULATION. 
By J. C. BRUNNICH, F.L.C. 
A Paper read before the Royal Society of Queensland 
on May 25th, 1907. 
In every station of life arithmetical calculations are abso- 
lutely indispensable: no trade, no profession, no calling, 
however humble it may be, can exist without a continual 
practical application of one of the three great R’s in the 
solving of arithmetical problems. Such calculations become 
in many cases a monotonous mental drudgery, and from 
the earhest times mathematicians have tried to invent 
instruments and tables which should minimise such work 
in all scientific, commercial and industrial calculations. 
In our present state of civilisation, in which the keen 
industrial competition becomes a veritable struggle for life, 
with ‘“‘ time is money” as its principal motto, such aids 
become more than ever invaluable, and I can positively 
state from my own experience, that with the help of graphical 
tables and more particularly with the use of slide rules, 
I have saved 75% of the time otherwise spent in calcula- 
tions. 
The object of this paper is to spread the knowledge 
of such instruments and to awaken the interest of a few, 
so that they lke myself become apostles advocating the 
employment of graphical tables and of slide rules. This 
paper does not claim to be a scientific treatise on the subject, 
neither can I enter into explanation of the more expensive 
instruments, like arithmometer, used _ for complicated 
astronomical calculations, and the elaborate adding or 
counting machines, which are more and more introduced 
into the offices of our larger banking institutions. 
C—Rovat Soc. 
