Dec. 8, 1870] 

NATURE 
105 

by Professor Young in the solar corona, The lines C and F 
having already been observed, the discovery of the line G seems 
to render certain the existence of this gas in the Aurora. The 
common methods of interpolation were rot available for com- 
puting the wave-lengths of column three, on account of the large 
interval between the lines. A curve was therefore constructed, 
in which vertical distances represented scale-readings, aud hori- | 
zontal distances the square of the reciprocal of the wave-lengths. 
This, by the formula of Cauchy, should be very nearly a straight | 
line, giving, consequently, results of great accuracy. 
EDWARD C, PICKERING | 
ON the evening of Monday, October 24, a very remarkable 
auroral display was observed in New York City, In the north | 
at first was an obscure segment, low towards the horizon, sur- | 
mounted by a pale glow of light. Later, this was replaced by an 
extensive manifestation of beautiful streamers. ; 
But the most notable part of the phenomenon was a band of 
brilliant red light, varying in its different parts constantly through- 
out the evening, in brilliancy, definition, and breadth, but in 
general some ten degrees wide. It was seen early in the evening, 
and could be traced from within fifteen degrees of the horizon in the 
east and the west, extending entirely across the sky, south of 
the Zenith. 
The position of this rosy band viewed from the south-east 
corner of the Central Park, was from 8} to 8} p.m., New York 
City mean time, about as follows. : 
In the east, just above the horizon, passing almost centrally, 
and diagonally through the figure pf Cetas, say between 6 and 
€ Ceti ; thence going westward it lay between Pésczs occidentalis 
and y Aguart’, and between Altair and Delphinus, often ex- 
panding in width beyond these boundaries. Thence it extended 
westward to the stars in the heads of Hercules and Serpentarius 
nearly to the horizon. 
In all its sptendid variations throughout the evening, it main- 
tained its position in regard to the horizon of the observer stand- 
ing in the locality before mentigned, the diurnal motion of the earth 
carrying the stars past it. 
On the following evening the exhibition of this red band, in the 
same position, was at least equally pronounced ; but without any 
decided boreal light, so far as [ have noticed or learned. 
{ would also here mention the very brilliant display of variously 
tinted auroral streamers which engaged the admiration of members 
of the American Association for the Advancement of Science, as 
they returned by the steamer on the Hudson to the city of Troy, 
from their visit to Albany, from ten to eleven o’clock on the 
evening of Friday, August 19, 1870. James Hyatt 
Honey Brook, Stanfordville P.O., New York 
Early Mentions of the Aurora Borealis 
Your correspondent, Mr. Karwaker, should have mentioned 
that the list of appearances of the Aurora Borealis given in M. de | 
Mairan’s work is chiefly derived from another enumeration in | 
Prof. Frobes’s **Nova et Antiqua Luminis atque Aurore | 
| and that the 

Borealis Spectacula,’ Helmstadii, 1739. On reference to this list 
it immediately appears that it is very little to be relied upon for | 
displays previous to the year 1707 or thereabouts. Some of the | 
appearances recorded rest on no good authority, others v ere | 
obviously meteoric; some occurred within the Arctic circles, | 
others are entered twice over from inadvertence, or a neglect to 
allow for the difference of style; more than twenty are recorded on 
the authority of the meteorological diary kept at Breslau by 
Grebner, who in fact says nothing more than that on those occa- 
sions the night was somewhat bright (swd/ustris). When the 
necessary deductions on these accounts have been made, it will be 
found that the infrequency of the phenomena prior to 1707, and 
its extraordinary development since that date, are well-estab- 
lished facts. They are strongly insisted upon by M. de Mairan 
himself, who does not produce more than five instances of the 
aurora in France during the whole of the seventeenth century, 
and shows from the evidence of a missionary that it was unknown | 
or forgotten in China until 1718. All contemporary notices prior 
to about this period, attest the astonishment with which it was 
regarded. 
From the following curious passage in Sirr’s ‘‘ Ceylon and the | 
Cingalese” (vol. ii. p. 117), it would appear that the aurora, or 
something resembling it, is occasionally visible in Ceylon :— 
‘** There is a heavenly phenomenon which appears occasionally 

in Ceylon, called by the natives Buddha lights; this faintly 
resembles the Northern Lights, and is extremely resplendent. 
The priests declare this to be a sign of Buddha’s displeasure 
when his followers have become sinful in the extreme, and that 
the light appears over the wihare, from whence the priests sup- 
| pose the phenomenon to emanate, where those who have com- 
mitted the sin which has aroused the god’s anger last wor- 
shipped.” 
London, November 19 R. G. 
IN many parts of Ireland a scarlet aurora is supposed to be a 
“‘shower of blood.” In 1854 while stationed at Bearhayen, 
County Cork, a scarlet aurora that then appeared was said to be 
the blood of the people that were slain at Balaclava. About 
two years ago, while driving between Oughterard and Clifden, 
at two o’clock in the morning, there was a magnificent scarlet 
aurora (by far the most brilliant I ever saw), on which the car- 
driver remarked, ‘I wonder, can that be the blood of the 
Americans?” The late aurora is said to be the blood of the 
Frenchmen. 
In the old Annals showers of blood are recorded at different 
times, always in connection with a great battle or the murder of 
some great chief. The earliest I can remember is that of A.D. 
688, in the ‘Annals of Cloonmacnoise,’’ after a batrle of the 
Leinster-men and Os-ory-men (now in the King’s County, but 
formerly in Munster), wherein Foylcher O’Moyloyer was slain. 
This battle and shower of blood in the “ Annals of the Four 
Masters,” is said to have happened in the year A.D. 690. These 
Annals also mention that butter was turned into the colour of blood 
and a wolf was heard to speak ; while the Annals of Tighernach 
place the battle in A.D, 693, and say that the blood flowed in 
streams for three days and three nights. During the aurora [I 
saw about two years ago, and the two nights that the last aurora 
was seen here, the lakes and rivers looked to be full of blood. 
Therefore I should imagine the aurora of 688 must have lasted 
three nights, and that the people who saw it and recorded it 
must have had butter for supper the night it was seen, which re- 
flected the colour. G. Henry KINAHAN 
Geological Suryey of Ireland, 
Connemara, Noy. 26 
Prismatic Structure in Ice 
THE following extracts from a letter from Mr. [Langton (whose 
name was, unfortunately, misread as Langters in sending his 
former letter to the press) may interest others as much as it has 
done myself, if space can be found for it in your columns. In 
| that case, perhaps, you will kindly allow me to say a few words 
in reply on a future occasion. 
St. John’s College, Cambridge T. G. Bonnry 
**T admit with you that the prismatic structure of ice 
on the point of melting does not appear to have any con- 
nection with the hexagonal crystals in which it is formed ; 
great analogy between the conditions of ice 
in that state and of igneous rocks, and I may add of clay in 
the process of desiccation, seems to point to contraction as the 
common cause. But then arises the question whether ice really 
does contract as it approaches the melting-point, as we know 
that most melted mineral matter does on cooling, and clay on 
drying. Iam quite willing to admit that it may do so, and that, 
as you observe, its demeanour at a point about 32° F. has not 
been accurately ascertained ; but if so, the fact should first be 
determined from independent observations before drawing con- 
clusions from it. I am willing also to admit that I spoke loosely 
in my former letter when I said that the air bubbles in the pro- 
cess of freezing seemed to be formed in vertical lines. My 
object, in the concluding sentence of that letter, was to express a 
doubt as to there being any such contraction as you suppose on 
the ice approaching the melting-point, and to point out the lines 
of air bubbles as being the immediate cause of the structure of 
rotten ice. I did not then go into the origip of the bubbles, or 
into the cause of their being thus found in vertical lines. It is 
difficult to suppose that they were originally formed in those 
lines, for though it seems natural that the air, which is always 
contained in water, should be excluded on its crystallising, there 
does not appear to be any sufficient reason why the bubble cx- 
cluded to-day should be placed exactly under that formed yesterday. 
Upon reviewing the whole question, I am induced to think that, 
as will often happen, we were both right and both wrong : that 
you were right in attributing the prismatic structure originally ‘o 
