March 8, 1883] 
NATURE 
431 
westward met with it in Europe and carried it onward. 
Cats seem also to have originated in Eastern Europe ; 
they are found not earlier than the Bronze Age in Switzer- 
land. From Pliny’s mention that the Germans used oat- 
meal, it is concluded that it was not cultivated by the 
Romans. 
Space will not allow of my giving an idea of the method 
by which these results are arrived at. But they seem to 
me to take advantage of every line of evidence and to be 
as near the truth as we are at present likely to approach. 
De Candolle sums up with great pains the philological 
evidence which he has collected from the best quarters, 
and though, as he is prepared to admit, a professed philo- 
logist might handle the evidence in a different way, he 
claims that the inferences he draws are such as are fairly 
within the competence of instructed common sense. And 
controlled as they are by other lines of inquiry they do 
not seem to me to be pushed toa point where, except in 
the hands of an expert, they would be likely to prove 
treacherous. It is obvious that the philological evidence 
alone might make the most careful go astray. The two 
instances given by Tylor are, ina way, a case in point. 
“ Sometimes,” he remarks, “ this (the name) tells its story 
fairly, as where damson and peach describe these fruits 
as brought from Damascus and Persia.” This is true 
perhaps as far as it goes. The cultivated plums of Damascus 
had a reputation in the time of Pliny ; but the wild stock 
does not extend to the Lebanon, and its home was probably 
far tothe northin Anatolia and Northern Persia. As tothe 
peach, De Candolle points out that its having no Sanscrit 
or Hebrew name is against an origin in Western Asia, 
and he gives a considerable body of evidence pointing to 
China as its true native country. 
It is in fact the indirect evidence given by such names 
through their origin and history which is of use, not the 
actual information they imply. The Jerusalem artichoke 
is a well-known instance. As De Candolle says, it is not 
an artichoke, and being a North American plant can have 
nothing to do with the Holy Land. The plant is techni- 
cally a sun-flower (He/¢anthus), though in our climate it 
rarely betrays its affinity by flowering. And the ordinary 
explanation is that Jerusalem is a corruption of Gzvaso/e. 
But this seems to be a wanton piece of euhemerism ; 
there is no evidence that the Italians ever used such a 
name for it, and the real explanation seems to be that 
Jerusalem was applied in a vague way, like Indian or 
Welsh, simply to indicate a foreign origin. Thus an old- 
fashioned garden plant (PA/omzs fruticosa) is called sage 
of Jerusalem with about as little reason. And in France 
the term Jerusalem artichoke is applied to a species of 
gourd. 
The second work which I have cited at the head of this 
article deserves a more extended notice than it is possible 
to give it. It is safe to say that only in France could 
such a book be produced, either as regards the share of 
authors or publishers. It isa sort of complement to De 
Candolle’s treatise, describing, from the cultural point of 
view (but with botanical references apparently carefully 
accurate), the various esculent vegetables which are 
known, with all their typical varieties, including even 
such sorts as are rarely seen in the gardens of cool 
countries. It is a book which any botanist will find a 
trations, which contrast so strikingly with the coarse 
ostentation of the ordinary trade catalogue. 
Weel ek) 
OUR BOOK SHELF 
Useful Rules and Tables relating to Mensuration, En- 
gineering, Structures, and Materials. By William 
John Macquorn Rankine, C.E., F.R.S., &c. Sixth 
Edition, thoroughly Revised by W. J. Millar, C.E. 
With Appendix, Tables, Tests, and Formule for the 
use of Electrical Engineers, by Andrew Jamieson, 
C.E., F.R.S.E. (London: Charles Griffin and Co., 
1883.) 
WE learn from the title-page of this edition of 
Rankine’s well-known book of Rules and Tables that 
it has been thoroughly revised, but we are sorry to find so 
little evidence of this in the work itself. Many of the 
rules given in this book are only applicable in particular 
cases, and generally no explanation as to this is given. 
Take for example Rule XXV., p. 211, which gives the 
9672000 X thickness? 
length X diameter 
This rule is evidently based on Fairbairn’s experiments, 
which were made on tubes with closed ends and of 
lengths in no case exceeding ten times the diameter. The 
rule as it stands is simply absurd, for it gives zero col- 
lapsing pressure for infinite length. The addendum to 
Part II. p. 367, referring to springs, may be taken as 
another example. Straight springs cannot be treated by 
the formulze given for beams unless they are only slightly 
bent, and again, the ratio of the force to the elongation 
produced by it ina spiral spring is that given by the formula 
only when the spires have small inclination to a plane 
at right angles to the axis. This formula is not even 
accurate, as the 7 in the denominator should be 77. Some 
estimate of the care bestowed on the work by the editor 
may be gathered from the following slovenly sentences 
taken from p. 374:—‘‘From experiments by Major 
Morant, R.E., India, it appears that only one-half the 
quantity of dynamite and one-third the number of bore- 
holes is required to remove the same quantity of rock as 
gunpowder.” “The area of the fire-grate being about 
145 square feet.” 
The Appendix on Tables, Tests, and Formule, for the 
use of electrical engineers, is a real addition to the book. 
Beginning with a table of the “ Formule of the Absolute 
Units,” Mr. Jamieson goes on to the definition of the 
different practical units now in use; and then gives a 
large amount of useful information in the form of tables 
and rules for making electrical tests. Much of the infor- 
mation here given is published for the first time, and on 
this account will be the more valuable to engineers. 
Cable work has received special attention, and although 
not fully treated, absorbs, we think, more than its due share 
of the sixty-four pages devoted to the appendix. The space 
taken up by some of the less useful tables might, it seems 
to us, have been saved, and a fuller treatment of the 
different methods of testing electromotive force, battery- 
and other resistances, &c., given. Mr. Jamieson gives 
only a few rules for such tests, and refers to other books 
for more, but we think that a book of rvles should be full 
if it be anything. In order to measure the resistance of 
thick wire, Mr. Jamieson suggests that a piece of it may 
be drawn down to a fine gauge, and then tested in the 
Wheatstone bridge. This is neither convenient nor satis- 
factory, and should be replaced by one of the well-known 
methods of testing such wires. Again on page 361, Mr. 
Jamieson proposes to measure the work done in charging 
a secondary battery by joining up a suitable voltameter 
as a shunt to it. This method is worse than useless. 
Although we should like to see an absence of such 
collapsing pressure of tubes as 
useful addition to his library, if only for the delicate illus- | faults as the above, and considerably more space devoted 
