APRIL 23, 1914] 
numerable industries depend for their existence. | bringing up the total to 7,556! 
In addition to its value as a text-book on domestic 
economy, it is well worthy of a place in every 
textile-worker’s library, and can be recommended 
as a reference book in the household. 
Wo. Scotr TaGcart. 
OUR BOOKSHELF, 
The Reform of the Calendar. By Alexander Philip, 
Pp. xiii+127. ‘(London: Kegan Paul, Trench, 
Tribner and Co., Ltd.,a9may) Price. 4s. 6d. 
net. 
Mr. Puivip reminds us that, apart from = minor 
notes, we have discussed different aspects. of 
calendar reform already in these columns (April 
27 and October 26, 1911). The reader who looks 
for enthusiastic advocacy of some change and an 
account of the various proposals which have been 
put forward in recent years may be referred to 
this little book on the subject. 
We wish to speak of Mr. Philip with some 
respect. Not that we regard calendar-making as 
a high order of achievement, although. Mr. 
Philip’s original scheme was probably as good as 
any other of its class, and.certainly a great deal 
better than some. But he has also the broad mind 
which appreciates objections and prejudices, and 
he has been led to reduce his first proposal to a 
minimum adjustment of the days of the months. 
The week is left undisturbed, and his present 
scheme may be represented thus :— 
Feb. 30 
Aug. 30 Sept. 30 
Mar. 30 April 31 
Oct. 31 
May 30 
Noy. 30 
June 30 (31) 
IDSs Bi 
Jan. 31 
July 31 
Perhaps something might be said in favour of 
interchanging the second and fourth quarters so 
as to bring leap day (when it occurs) to the end 
of the year. But little can be seriously urged 
against a change which makes the months and 
quarters more equal and introduces an approxi- 
mately rhythmic (? dactylic) arrangement. What 
is to be feared rather is that so slight an adjust- 
ment offers so small an advantage, in spite of 
Mr. Philip’s glowing optimism, as to lack the 
necessary driving force for its adoption. Does 
there indeed exist a _ practical middle course 
between the Scylla of traditional prejudice and the 
Charybdis of triviality ? 
Pe... P. 
Les Zoocécidies des Plantes d’Europe et du Bassin 
de la Méditeranée. By C. Houard. Tome 
Troisiéme. Supplément: | 1909-1912. Pp. 
1249-1560. (Paris: A. Hermann et Fils, 1913.) 
Price 10 francs. 
THE rapid progress of cecidology has led Prof. C. 
Houard to publish a supplement to his two in- 
dispensable volumes on the Animal Galis_ of 
Europe. This third volume deals with what has 
been done between 1909 and 1912, and it is as- 
tonishing to find a registration of 1,300 new galls, 
NOw gaa, VOL. Ogi 
NATURE 
SSS j_ 
4 
187 
The author has 
exercised discretion in what he has included, and 
he makes an appeal to those interested in galls— 
and what naturalist. is not?—to refrain from 
rushing into print with new discoveries until they 
have studied them for, say, two successive years ! 
Everything has been done in the way of double 
entry and bibliography to make the catalogue 
serviceable, and both pagination and enumeration 
are in continuity with the previous volumes. 
There are 201 illustrations, and there is an appro- 
priate frontispiece with photographs of Ribsaa- 
men, Kieffer, Massalongo, and the late Prof. 
Giard. 
The Principle of Relativity in the Light of the 
Philosophy of Science. By Paul Carus. Pp. 
105. (London and Chicago: The Open Court 
Publishing Co., 1913.) Price 4s. net. 
Tue author of this work has made up his mind 
in advance that the question of relativity is a 
philosophical problem. It is therefore necessary 
for him to dismiss contemptuously all the history 
of the purely physical principle technically known 
as. ‘‘the principle. of relativity.” . To say as he 
does that the Michelson-Morley experiment 
“assuredly has nothing to do with the principle 
of relativity’ is simply tc say that the principle 
is not what it is. The author refuses to call the 
principle a hypothesis, and asserts “that it is an 
a priori proposition, a postulate of pure thought 
which either holds good universally or has no 
validity whatever.”’ 
Whatever opinion may be held on this point, 
it is impossible to say that to the student of 
dynamics there is no difference in status between 
rotation and translation. If relativity is a require- 
ment of pure thought, why cannot Newton’s 
laws of motion be used equally well for two frames 
of reference, of which one is in rotational motion 
relative to the other? Are those laws wrong, or 
is pure thought irrelevant to dynamics? One as- 
pect of the principle of relativity is that we do know 
whether it is convenient to think of a system as 
having no rotation. This is a matter of common 
experience. If pure thought denies it, it is clear 
that it is thinking about something other than 
the facts with which experiment deals. 
Nature and the Idealist. Essays and Poems. 
By H. D. Shawcross. Pp. xii+186. (London: 
Sampson Low, Marston and Co., Ltd. n.d.) 
Price: ssi mer: 
Tue late Mr. Shawcross died last year at the early 
age of twenty-nine. He was a newspaper journ- 
alist whose work had to be done in a_ busy 
Lancashire town, though all his instincts and his 
love for nature would have taken him into the 
country. His essays and poems reveal much of 
the struggle he continually had and their merit 
suggests that had he lived longer he would have 
become known as a poet and essayist to a wide 
circle of lovers of nature. 
