290 
NATURE 
[JANUARY 24, 1907 
In those sections devoted to paper testing, which 
make up more than half the volume, the author takes 
pains to make his exposition lucid. We note an 
occasional slip, as in dealing with the question of a 
coloured ash left on burning a paper: ‘If blue, 
ultramarine, Prussian blue, or smalts may be pre- 
sent.’’ This must be corrected as regards the cyanide 
blue. Again :—‘‘the blue is tested by boiling with 
caustic soda and filtering.’’ ‘The Prussian blue 
passes into solution.”’ This inaccuracy will be 
evident to the chemist. 
In the section on the estimation of moisture we 
find the expression “bone dry’ for ‘oven dried.”’ 
Bones are not dry to the chemist, only to the poet. 
In the ‘dictionary of chemical terms’? and the 
“glossary of various papers”? which make up the 
concluding chapters we also note a number of slips, 
which perhaps may be explained by the laudable aim 
at short, crisp definitions; but this hardly excuses 
the description of caustic soda as ‘“ prepared by boil- 
ing carbonate of soda with quicklime”’; bleaching 
powder as a “dry pulverulent powder prepared by ex- 
posing dry powdered quicklime to chlorine gas ’’—the 
italics here are our “note of exclamation’; ‘“ dex- 
trine’’ as industrially obtained ‘by the action of 
boiling dilute sulphuric acid on starch”’; ‘ dicoty- 
ledon as including the Coniferae with angiosperms, 
such as beech and ash. 
These descriptive terminologies are excellent in 
plan, and generally useful. They should be carefully 
revised, and perhaps amplified, in future editions. A 
section on bibliography would be a useful addition, 
and we think it is due from the author to acknow- 
ledge more fully the sources of much of the matter in 
this book, especially the German text-books and publi- 
cations, of which he fully avails himself. The bool 
is fully illustrated, and the matter thereby pointed 
and elucidated. 
It is evident that the worl is one we can appreci- 
atively commend to the very wide circle of those 
interested in ‘‘ paper ’’; as for the paper-makers, the 
author only indulges, with becoming modesty, the 
“hope that this book may prove useful to them.” 
We think they will see the value of keeping pace with 
the critical knowledge of the consumers. 
WEIGHTS AND MEASURES. 
Outlines of the Evolution of Weights and Measures 
and the Metric System. By Dr. William Hallock 
and Herbert T. Wade. Pp. xi+304. (New York: 
The Macmillan Company; London: Macmillan and 
Co., Ltd., 1906.) Price ros. net. 
“1 Dae literature of weights and measures is very 
extensive, and, as a rule, singularly uninterest- 
ing. Messrs. Hallock and Wade are therefore to be 
congratulated on having produced a treatise on the 
subject which is at once instructing and attractive. 
For this is an admirable piece of work, in which the 
result of much tedious research is presented in a 
bright and lucid narrative. The first chapter is de- 
‘voted to a brief review of the speculations of metro- 
NO. 1943, VOL. 75] 
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logists and antiquaries concerning the weights and 
measures of the ancients. It includes a particularly 
good account of the Babylonian units and the various 
theories respecting them which have been deduced 
from the Senkereh tablet and the scale of Guldea. 
After a rapid survey of the weights and measures 
of the Hebrews, the Greeks and the Romans, the 
authors pass on to consider the systems in vogue in 
Great Britain and in France from the earliest times 
up to the end of the eighteenth century. The next 
two chapters and the fifth deal with the origin and 
extension of the metric They trace the 
system from its embryonic stage in the writings of 
Mouton, Picard, Huygens, and Cassini, to its fully- 
elaborated form in the law of April 7, 1795. The 
geodetic work of Delambre and Meéchain is next 
described, and the opportunity is taken to introduce 
short explanations of a trigonometrical survey and of 
the determination of latitude. An account follows of 
the construction of the metric standards of the French 
Archives and of the lengthy interregnum of mesures 
usuelles. 
system. 
The meeting of the International Geodetic Associ- 
ation at Berlin in 1867 marlkxs an important epoch 
in the history of the metric system. The authors de- 
scribe the influential part played by it in securing 
the establishment of the International Metric Com- 
mission. This leads to an interesting account of the 
International Committee of Weights and Measures 
and its bureau at Sévres. In this connection it may 
be mentioned that, owing to the death of the British 
representative early last year, this country is at pre- 
sent not represented on the International Committee. 
The power of appointing a member to fill the vacancy 
rests with the committee itself. In 1884 the com- 
mittee had some difficulty in finding a suitable re- 
presentative for this country owing to the fact that 
the officer in charge of our Standards Department at 
that time, although an official of standing, was com- 
paratively unknown in the scientific world. At the 
present time, now that all the metric prototypes have 
been distributed, and thus the most important object 
of the convention achieved, it is absolutely necessary. 
in order that the United Kingdom may continue te 
derive any advantage from its contributions to the 
funds of the Metric Bureau, that the representative 
of this country on the committee should be an official 
of the Government department which is charged with 
the construction and preservation of the Imperial and 
metric standards. It will accordingly, no doubt, be 
a matter of considerable satisfaction to the Inter- 
national Committee that the recently appointed 
Deputy Warden of the Standards is an eminent man 
of science, in every respect worthy of membership in 
that distinguished body which has included on its roll 
such names as Mendeléeff, Bertrand, Foerster, 
Maseart, Christie, and Michelson. 
In their fourth chapter Messrs. Hallock and Wade 
have set themselves the congenial task of explaining 
the standards of weight and measure in vogue in 
their own country. The desirability of a simple and 
uniform system of weights and measures was fully 
