104 
NATURE 
_ ae. | 
[ Dec. 8, 1870 

quarters of the globe, with a supplementary chapter on 
Nature and Man as agents of change. The second part 
is descriptive of the commercial products of the Vege'able 
Kingdom, in which Meyen’s plan appears again to have 
been followed in the main; it is subdivided into Food 
Plants, and Industrial and Medicinal Plants. In the third 
part we have, in like manner, the commercial products of 
the Animal Kingdom ; and, in the fourth, raw mineral 
products. The comments which we lrave to make are 
almost confined to errors of omission which can be readily 
rectified in future editions. We regret to see still re- 

tained the antiquated classification of the Animal Kingdom | 
into Vertebrata, Mollusca, Annulosa, Radiata, and Pro- | 
tozoa. The sentence by which (p. 260) the porcupine ard 
the ant-eater are made members of the order Monotremata, 
is no doubt merely an oversigtt. Among food plants, it 
is strange to find no mention made of the potato, nor, 
indeed, of any of our culinary vegetables, the cabbage, 
turnip, or carrot, with the single exception of the onion! 
We demur to the assertion that the morel is “one of the 
few fungi found in this country which may be eaten with 
safety;” among these few we do not understand why 
the truffle and the morel only are given, the mushroom 
not being even alluded to. Indeed, the whole subject of 
Vegetable Products requires revision, many being entirely 
omitted of much greater importance than others to which 
considerable space is allotted. Among Industrial Plants, 
for instance, we should expect to find some description of 
the numcrous fibres now used in the manufacture of paper, 
the esparto-grass, different kinds of wood, &c., which are 
daily becoming more important articles of commerce. 
An exceedingly useful vocabulary is appended, containing 
the names of natural productions in the principal Euro- 
pean and Oriental languages ; and the volume may be 
safely recommended as containing an immense mass of 
useful information on a very important subject. 
Record of American Entomology for the year 1869. 
Edited by A. S. Packard, Jun., M.D., 8vo. (Salem, 1870. 
London: Williams & Norgate.) 
THis is the second annual analysis of the literature of 
American Entomology which has been published under 
the care of Dr. Packard. It must be gratifying to entc- 
mologists to find that their science is so popular in the 
United States as to render the production of such a work 
at all feasible, and we can only hope that the Editor may 
receive sufficient support to enable him not only to continue 
it in its present form, but even to enlarge it and make it 
still more useful. Of course, with the general ento- 
mologist, this Record can never take the place of the 
entomological portion of the Zoological Record which has 
been brought out in this country since 1865, but it is of 
the greatest value in giving the European naturalist 
intimations of papers and descriptions published in those 
out-of-the-way American periodicals which rarely fall into 
his hands. Wiis ae 



LETTERS TO THE EDITOR 
[Vhe Editor does not hold himself responsible for opinions expressed | 
by his Correspondents. No notice is taken of anonymous 
communications. | 
The Aurora Borealis by Daylight 
I HAV® been expecting ever since the great display of Tuesday, 
* Oct. 25, to sce some statement that the Aurora was visible on the 
afternoon of that day. I was in Huntingdonshire, about four miles 
from Kimbolton, at the time, and being out of doors at half-past 
four P.M., saw a remarkable pale luminous appearance some 25° 
above the horizon and almost due east. At this point there 
were two arcs of faint white lines, one above the other, both 
raliating outwards with a number of shcrt points. The breadth 
of the wpper are (which was rather the widest) might be from 
twelve to twenty times the apparent diameter of the moon. Tt 
was of course broad daylight at the time, and the sky was per- 
fectly clear and cloudless for a long distance round these patches 
of light. ‘They were visible for at least ten minutes, brighter 
and fainter alternately, and were seen by a friend as well as my- 
self. I was unfortunately called away, and prevented from watch- 
ing them while the sky became darker. After dark (at 5.30) 





































































































































































































































































































































































































































































































































































































































































they had disappeared, but the dark irregular circle mentioned by 
Mr. Grove, from which the streamers radiated, was extremely 
It did not strike meat the time that the appear- 
conspicuous. 
But as it 
ance at 4.30 was likely to have any special interest. 
before the evevig display of the aurora, it may perhaps be of 
use to record that it was also visible in the latter part of the 
afternoon. 
26, Finsbury Place, E.C. 
James Cusirr 
The Spectrum of the Aurora 
THE following observations on the Spectrum of the Aurora were 
made by Mr. Alvan Clark, jun., in the neighbourhood of Boston, 
on the evening of October 24. He used a chemical speciro- 
scope of the ordinary form, with one prism, and photographed 
scale illuminated with a lamp. Four lines were seen at the 
points marked 61, 68, 80, and 98. To reduce these to wave- 
lengths, the next day I measured the lines C, D, E, b, F, and G 
with the same instrument, and deduced the annexed table :— 






| 
Wave- = Assumed | | 
Line. | Reading | length nes Comments. | Error. 
EE 5 ee ees rey 
c 491 | 656 | | 
| D 578 583 | 
(uv 6c 563 557 Common Aurora Line | — 2° 
(2) 68 532 5316 Corona Line ? +1 
bb 6) 527 | 
b gue. 4 517 | | 
¥F 797 486 
) 'F Hydrogen, —"3 
(4) 08 | 435 434 G me +°6 
G | 100°5 431°2 j 






The first column gives the name of the line; the second the read- 
ings on the scale; the third its wave-length, obtained from 
Anystrém’s chart, and by interpolation; the fourth the wave- 
length of the line with which these lines are supposed to be 
identical. The ffth column gives the name of this line, and the 
Fn error in parts of the scale. The first measure is 
x2 
wo 
co} 
+ 
‘00 
a 
a 
o 
a 
evidently wrong, and should probably have been 63. For the 
other three, however, the agreement is remarkable, two coming 
close to F and G of hydrogen, the other to the line observed 
seems that the greatest disturbance of the telegraphs happened _ 
ee 

