AUGUST 22, 
date in his chapter devoted to the internal com- 
bustion engine, for he describes that latest, most 
ingenious, and economical pump due to Mr. 
Humphrey. This volume should prove very wel- 
come to engineering students. The illustrations 
are excellent, and numerical exercises with their 
answers bear upon the principles discussed in each 
chapter. 
(2) Many of those who have not given attention 
to the subject are still under one of two false 
impressions concerning destructors and the dis- 
posal of city waste. Either it is supposed that a 
destructor has no other utility than getting rid | 
of the leavings of our streets and houses, or else 
that the calorific value of refuse is so low that to 
make electricity out of it would be impossible, or, 
in fact, to use the heat generated for any other 
useful purpose. The book before us will tend to 
dispel such impressions, and the reader will be 
grateful to Mr. Goodrich for putting together 
much information concerning the construction, 
working, and economy of destructors in Great 
Britain, the Continent, and America. It will be 
gratifying to English engineers to learn that the 
author is “able to place on record the proved 
superiority of the British destructor in many coun- 
tries.” He shows how, one by one, city authorities 
are abandoning the methods of land and sea 
dumping, and are adopting some kind of incinera- 
tion as the best means for disposing of waste. 
In connection with sewage works, it has been 
found that, unless the lift is very high, the refuse 
burnt in a destructor will maintain steam for pump- 
ing, and Epsom is cited as a case in point where 
not only is the sewage of the town dealt with, 
but that of several large institutions of the London 
County Council. The tables of costs in connection 
with electricity works are especially instructive as 
showing what may be done towards reducing the 
coal bill by burning refuse. It would perhaps have 
been better if the analysis of refuse from American 
cities had been compared with that from English 
cities, and some deductions drawn therefrom. The 
descriptions of actual destructors, which occupy 
the greater part of the volume, show what strides 
have been made in recent years. 
(3) This bulky volume on heating and ventila- 
tion should possess some interest to others than 
those connected with the heating and ventilating 
trades, but it is so loaded down with empirical 
formule that it requires a nice discrimination on 
the part of the reader to separate the chaff from 
the wheat. It might, indeed, be regarded as a 
treatise on the physics of the subject, though much 
of the subject-matter, especially the elementary 
matter at the beginning, might safely be omitted. 
It is generally superficial, though the author may 
NO. 2234, VOL. 89] 
NATURE 
iy 
629 
be excused from this charge on the ground that 
he has to crowd in such a mass of material. A 
work of this description should prove advan- 
tageous, as so much of our heating and ventilation 
is done in a haphazard and unscientific manner. 
PSYCHOLOGY IN BUSINESS. 
Increasing Human Efficiency in Business. At Con-’ 
tribution to the Psychology of Business. By 
Prof. W. D. Scott. Pp. v+339. (New York: 
The Macmillan Company; London: Macmillan 
and Co., Ltd., 1911.) Price 5s. 6d. net. 
HIS work is a genuine attempt to develop 
the application of reasoned methods to the 
organisation of the human element in industry 
and commerce. The opening chapter, on “The 
Possibility of Increasing Human Efficiency,” sets 
out with the proposition that the output of work, 
whether of brain or muscles, by the average indi- 
vidual is very far below the maximum possible; 
that in most cases the individual would gain in 
health and happiness if his efficiency were judi- 
ciously developed, and that the general gain to 
the community through this development would 
be correspondingly great. In the concluding para- 
graph of this chapter the author says: ‘In the 
succeeding chapters will be described specific 
methods, many of which are employed by indivi- 
dual firms, but which could be used by other busi- 
ness men, to ensure their own efficiency and that 
of their employees. The experiences of many suc- 
cessful houses will be linked to the laws of psycho- 
logy to point to the way that will bring about 
greater results from men.” In the eight chapters 
which follow, “Imitation,”  ‘ Competition,” 
“Loyalty,” “Concentration,” “Wages,’’ 
‘* Pleasure,” ‘‘The Love of the Game,” and 
“Relaxation ’’ are treated of as means of in- 
creasing human efficiency. The final chapters deal 
with “The Rate of Improvement of Eiticiency,” 
“Practice plus Theory,” “Judgment Formation,” 
and “ Habit Formation.” 
The author makes no attempt to define the 
sense in- which he uses the term efliciency. For 
the most part it appears that he is considering 
efficiency from the point of view of the business 
organiser or from that of the type of manufac- 
turer ‘““whose razors may be made to shave, but 
certainly must be made to sell.” But that other 
criteria of efficiency are not absent from the 
author’s mind is evident from the outset, for in 
the first chapter the illustrations of efficiency are 
often culled from regions of human activity very 
far removed from commerce and industry. For 
example, on p. 13 the walk of Mr. Weston, aged 
zo years, from New York to San Francisco, at 
