DECEMBER 24, 1896] 
NATURE 
173 
measures is obtained, the British system will drop out 
of existence as a natural consequence of the elimination 
of the unfit. Prof. Wagstaff not only describes clearly 
the metric measures, but he also brings together a number 
of facts and expressions of opinion for and against their 
introduction into the British Isles. 
The Aurora Borealis. By Alfred Angot. Pp. xii + 
264. (London: Kegan~Paul, Trench, Triibner, and 
Co., Ltd., 1896.) 
THIs is a translation of a book—“ Les Aurores Polaires” 
—reviewed in this column in March 1895 (vol. li. p. 484). 
It is the eighty-first volume of the International 
Scientific Series, in the list of which it is correctly 
entitled “The Polar Aurora,” instead of ‘‘The Aurora 
Borealis.” Only upon the title-page and cover does the 
latter designation appear, each of the pages with even 
numbers bearing the former title. This inconsistency 
will probably lead to some confusion. 
A comparison of the present volume with the original 
edition shows that the translation has been well done. 
We have, as the result, an interesting and lucid account 
of the present state of knowledge of the aurora in all its 
aspects, illustrated by pictures of the typical forms 
assumed. In an appendix, a list is given of the aurora 
seen in Europe below latitude 55° from 1700 to 1890. 
An index would be a valuable addition to the book. 
Ros Rosarum: Dew of the Ever-living Rose. 
+ 292. (London: Elliot Stock, 1896.) 
A SECOND edition has been issued of this delightful 
little volume. It contains extracts from works of poets 
whose songs have come down to us from all ages. In 
the interesting introduction the author states that many 
of the translations are due to the kindness of Lord 
Tennyson, Lord Lytton, Mr. J. A. Symonds, and many 
friends. Much information is also given concerning the 
history of the rose, and it is shown how highly this 
flower has been regarded at various times and in various 
countries. In both Athens and Rome it was recognised 
as the queen of flowers; there seems, indeed, to have 
been scarcely a time when it was not valued and appre- 
ciated. The book will be found very interesting ; the 
quotations have been carefully collected and placed, as 
far as possible, in chronological order. It may also be 
added that one quotation from Lord Tennyson is not to 
be found in his collected works, a fact which adds interest 
to the little volume. 
Pp. xxix 
Knowledge. Vol. xix. January to December 1896. Pp. 
288. (London: Anowledge Office.) 
WE offer our congratulations to the editor of Anow- 
Zedge upon the completion of this very attractive volume. 
The illustrations—many of them full-page collotypes— 
are most instructive pictures, and the figures in the 
text are just as good. The remarkably fine reproduc- 
tions of astronomical photographs are particularly inter- 
esting. A series of twelve well-illustrated articles by- 
Mr. Vaughan Cornish, under the comprehensive title of 
“Waves,” also calls for special mention. It is not pos- 
sible to keep up with the march of science in a monthly 
periodical ; but Avowledge gives a good general idea 
of progress, and the present volume is full of interesting 
articles on comparatively recent work, illustrated by some 
of the best pictures it is possible to obtain. 
Hygiene Diagramettes. By W. H. Knight. 
Chapman and Hall, 1896.) 
THIS is a colleetion of twenty-four photo-zincograph 
reductions from large diagrams designed for teaching 
hygiene. Upon the page facing each of the illustrations 
are given brief descriptions of the separate drawings 
and tables. These notes, together with the instruc- 
tive diagrams, should be very serviceable to teachers 
and students. It is a pity that the inscriptions attached 
to some of the illustrations are illegible, owing to the 
reduction of the originals having been carried too far. 
NO. 1417, VOL. 55 | 
(London : 
LETTERS TO THE EDITOR. 
[Zhe Editor does not hold himself responsible for opinions ex- 
pressed by hts correspondents. Neither can he undertake 
to return, or to correspond with the writers of, rejected 
manuscripts tntended for this or any other part of NATURE. 
No notice ts taken of anonymous communications. | 
Leonids of November 15, a.m., 1896. 
THE display of Leonids on the morning of the 15th ult. was 
observed here under very favourable conditions of the sky for 
noting the progress of the shower in numbers and in brightness, 
and in the position and distinctness of the meteors’ radiant-point 
or centre of divergence. As observations of this kind collected 
in the present early stages of the shower’s gradual increase to 
greatest brilliancy seem likely to be very useful to improve our 
knowledge of the past history and mode of advent of this 
meteor-stream into the solar system, I send the following 
leading particulars of the shower as it was here observed. 
The sky was cloudless during my watch from midnight until 
dawn appeared rapidly at six o’clock on Sunday morning, the 
15th, excepting only in the hour from 44 to 54 a.m., when 
clouds spreading slowly hid nearly all the sky in the latter half 
of the hour, but dispersed quickly then in time for a perfectly 
clear half-hour from 54 a.m. till daybreak. At this latter time 
the radiant in Leo, then preceding the mean sun as it did, about 
six hours in R.A., had reached its highest southern altitude of a 
little over 60°, or nearly that of the sun at midday in midsummer, 
while in the hour from midnight to 1 a.m. it was, like the sun in 
June-July at 6-7 in the morning, 20° to 30° above the E. by N. 
horizon, having risen above the horizon in that quarter a few 
minutes after ten o’clock. The moon, however, a little past her 
first quarter, shone strongly still in the west, hiding 5th magni- 
tude stars till one o’clock, and only set, leaving the sky quite 
clear, at about 1.45 a.m. It may be owing to the obstacles 
of clouds in one, and of moonlight in another hour of the 
watch, that only one Leonid was recorded in each of the 
two hours from 44 to 54, and from 12 to I o’clock ; but observa- 
tions made elsewhere under better sky conditions, by Mr. W. 
H. Milligan in Belfast, and by Mr. H. Corder at Bridgwater, 
show that there were really lulls in the shower’s intensity before 
2, and towards 4 o'clock, though it regained its brightness in 
the later hour from 5 to 6 o’clock; and neither the compara- 
tively low altitude of the radiant-point, nor the moderate 
strength of moonlight till 2 o’clock seem sufficient to account 
satisfactorily, considering the brightness of most of the meteors 
which showed themselves very little later, for the marked 
scarcity of Leonids noted in the first two hours of the watch. 
The following numbers of Leonids and of sporadic or non- 
Leonid meteors were recorded (and most of theirapparent paths 
were mapped) in the successive hours (or half-hours) ending at 
r (x4) (2) 3 4 (42) 
I I 2 7 5 
Ir 
5% (6) a.m. 
Numbers of Leonids x 6; Total, 34 
Numbers of Sporadic 
AWeteorsitssl iss axecu ee Oar 2) SKS Ay ae 
Ratio of Leonids to Sporadic Meteors, nearly 3 :1. 
Hourly Numbers of 
Leonids ... I 2-4 mz 7 (10) [*2] (12); (*, cloudy}. 
Meteor-magnitudes. : 
Equal to ir Q@ % Sirius rst 2nd 3rd 4-sth. 
Numbers of Leonids mart 2 6 8 5; Lotal, 34 
Numbers of Sporadic 
Meteors eS _- -— —_ — I 2 Ose asa, Le 
The second table shows how much the Leonids surpassed in 
brightness, as they also did in numbers, the ordinary appearances 
of shooting stars on a November night. The brightness of the 
display, and its rather sudden commencement, apparently at 
about 2 o’clock on the morning of the 15th inst., seem to point 
to that morning as having been at least a very conspicuous date 
of its return this year, although eager expectation of a shower on 
the morning of Saturday, November 14, was awakened in the 
1 English Mechanic, November 27, 1896 :—‘‘ From 12} to 2” (? Irish 
time, = 1-2} English time) a.m., Mr. W. H. Milligan noted ‘‘g Leonids ; 
hourly number about 6.” This was a rather low rate of appearance in 
that period. Mr. Corder began watch at 2 o'clock, and saw eight Leonids 
and two sporadic meteors in the first half-hour, “after which the numbers 
fell off; but when the radiant had risen higher, about 5 to 60 clock, 16 
meteors were seen in an hour, nearly all Leonids.” Descriptions of the 
shower's appearance on the preceding morning (of November 14), by Mr. 
Corder and Mr. E. R. Blakeley, in the same issue of the Engdish Mechanic, 
and descriptions of the apparent paths of several bright Leonids seen in a 
clear hour at daybreak on November 15, by Mr. W. E. Besley, at Waltham- 
stow, in the next preceding number of the same journal (November 20), 
are extremely interesting in this connection, and will presently be again 
referred to. 
