2096 
NATURE 
[JULY 24, 1902 
most gorgeously coloured, long-enduring sunsets, of the times 
of the conspicuous red glows’ commencements ; but this average 
interval appreciably surpassed the shorter space of 25-5om. (as 
did also the fading-out duration of nearly an hour exceed that 
of only 20-25m.) observed in last month’s displays; and the 
computed heights accordingly of the glow-producing matter 
ranged considerably lower (from 5 or 8 to 13 or 20 miles) in 
these latter than in the memorable sunset glows which followed 
the great eruption in Java on August 27, 1883, when heights 
appear to have been found of 13 or 17 to 25 or 30, or even 
possibly of 40 or 70 miles, for the strata of the atmosphere 
contaminated with volcanic dust. 
The relative height results and the comparative intensities of 
the present and of the former glow displays seem, however, to 
have been in quite naturally comprehensible agreement with the 
lower height of projection, and with the generally lesser magni- 
tude of the recent fearfully destructive outburst on the islands of 
Martinique and St. Vincent, when compared with the terrifically 
violent and immense volcanic explosion of Krakatoa in August, 
1883, which is generally admitted to have had no previous 
parallel, in respect of scale and violence of mountain-mass 
ejection, in the history of such terrestrial convulsions. It will 
be interesting to notice on future nights if more examples of 
rose-red coloration should occur, when the times of the white 
and yellow sky-tracts becoming pink and ruddy should be noted, 
as the past month’s rosy and fire-tinted sunsets were perhaps not 
quite sufficiently conspicuous to establish their certain connec- 
tion with the terrible volcanic catastrophe of May 7-8 last in the 
West Indies. But considering the low temperature and continued 
cold soaking rainfall during all the early part of last month, until 
Sunday, June 22, it seems far from easy to conceive that the 
strikingly fine sunset display of Thursday, June 26, and the 
conspicuously rosy colorations of the sunset sky on June 27 and 
28 can by any possibility have been merely sunset glares pro- 
duced by ordinary floating dust raised locally from parched or 
arid tracts of land by the heat and fresh east wind of those few 
days of the first short interval of summer warmth and sunshine 
in Jast month, on which they were observed. 
Observatory House, Slough, July 10. A. S. HERSCHEL. 
P.S.—July 16.—A very fine display of orange-reddish 
streamers diverging in an open fan of six or seven stately light- 
beams from a similarly coloured horizon glow, 6° or 8° high at 
their common base where the sun had set (at about 8h. 15m.), 
was seen here on Monday evening, July 7. From 8h. 50-55m., 
when these fiery-looking beams began to appear, up to altitudes 
of about 35°, across a rosy tract of sky which had sunk to the 
elevation of their growing crests from a higher region of pink 
colour first distinctly well perceived at 8h. 42--44m., their radiant 
light-sheaves shortened gradually without change of place or 
brightness; and they lasted thus quite 20m., retreating 
slowly into the decreasing glow at the horizon until that glow 
itself, at last, grew quite low and dull at 9h. 15m. The pink 
glow’s lower border, when the first bands of streamers crossed 
it, Was not more than 10° or 12” from the horizon, and the glow’s 
red hue soon permeated all the yellow belt of sky which lay 
below it, while the streamers, at their heads, grew orange-red 
in place of pink, and thus from 8h. 50-55m. onwards, the whole 
display, until it subsided, was of one bright pinkish-orange tint 
in all its features. The new moon’s very slender crescent, at 
Sh. 55m., lay less than 1° from the horizon, under the end part 
of the most southern streamer, looking pure yellow, and showed 
by its clear visibility how free from mist and smoky haze the 
sky was on that evening quite close to the horizon, 
From the pink glow’s first appearance at 8h. 43m, with an 
altitude of about 35°, at about 28m. after sunset, the resulting 
real height of the layer of dusty air which was thus lit up by the 
sun’s departing rays, could not much exceed 5 miles above the 
earth’s surface. On other dates in July before and since that 
notable appearance, the observed occurrences of a pink tinge in 
the sunset sky were scarcely noticeable, and the estimated time 
of its first appearance was only once thought to be prettycertainly 
trustworthy, on Sunday, July 13. A rosy tinge then first pre- 
sented itself pretty brightly at Sh. 41m., about 33m. after sunset, 
at about altitude 40°, sinking down along-the heads of some 
nearly vertical wide streamers, in three or four minutes to altitude 
15'~20°, where it soon died away. The height of the mauve- 
coloured haze-stratum in the atmosphere which this observation 
pretty nearly indicated would seem to have been about 7 or 8 
miles. 
NO. 1708, VOL. 66] 
In addition to the above short notes of some particular ac- 
counts contained in NATURE of the bright sky-glows of November 
and December, 1883, it was observed, I find also, by Mr. 
E. Douglas Archibald, at Rusthall, near Tunbridge Wells 
(NATURE, vol. xxix. p. 176), that after sunset (at about 3h. 51m.) 
on December 6, a bright silky-looking white space in the clear 
sunset sky changed to pink at 4h. 25m. (34m. after) and to red 
at 4h. 45m. (54m. after sunset), which would imply heights of 
the pink and red glows of about 8 and 21 miles above the 
earth, But from the appearance of the glow on December 7 
and of its reflection on low clouds, Mr. E. D. Archibald re- 
marked that the red light’s long continuance after the pink glow’s 
departure was mainly attributable to cloud or haze reflections of 
true redcoronal glaresabout the sun ; and the conspicuous tinging 
of the white space with pink or rosy iridescence he concluded, 
from the interval between the concluding glow of ordinary 
cirrus and the commencing glow of the loftier dust stratum, cor- 
responded more nearly with a height of from 10 to 13 miles, 
than with the great height of 40 miles assigned to the glow 
(probably from long-lasting reflection of red glows in the west 
on low-lying clouds, or perhaps even on the high dust stratum 
itself) by Brof. von Helmholtz. 
Distribution of Pithophora, 
In your Notes of July 17 you state that Mr. Kumagusu 
Minakata wishes to knowif any species of the genus Pithophora 
besides P. Aewensis has been reported from any part of the 
Old World except Japan since 1877. 
P. radians, West and G.S. West, was described from Loanda, 
onthe west coast of Africa, in Jorn. Bot. (January, 1897, p.36), 
and has more recently been found in Ceylon (cf. Zyavs. Linn. 
Soc., bot. ser. 2, vol. v., 1902, p. 132). LP. Rezneckt?, Schmidle, 
was described from Samoain Engler’s Bot. Jahrb. (xviii., 1896). 
Schmidle has also described at least one other species from the 
Old World, but I have not the reference to hand. It will be 
found within the last five years either in Engler’s Bot. Jahrd. 
or in “ Hedwigia.” G. S. WEsT. 
Royal Agricultural College, Cirencester, July 18. 
Saturn Visible through the Cassini Division. 
In Nature of May 22 you were good enough to publish my 
prediction that, on July 17, the Cassini division of Saturn’s ring 
would be invisible where it crossed the planet, 
On July 15, Mr. Townshend, president of the Leeds Astro- 
nomical Society, reports that he saw the division throughout 
the ring and crossing the globe, but that on the 17th the portion 
crossing the globe was invisible. Mr. Townshend observed 
with a 10-inch reflector, and is a very competent observer. 
On July 17 I was observing with a 9-inch refractor, and the 
Cassini division, clearly seen in the ansze of the ring, was quite 
invisible in that part of the ring which crossed the globe. 
I shall be very glad to receive notes of other observations of 
Saturn made on July 17, and shortly before and after that date. 
Invermay, Leeds, July 21. C. T. WHITMELL. 
THE ELECTRIFICATION OF LONDON. 
pee various electric railway Bills which have already 
passed through the House of Lords came up for 
second reading in the House of Commons last week. 
In spite of some attempts to reject several of these Bills 
they all successfully passed the second reading and have 
been referred to two Select Committees of the House of 
Commons. These Committees, each of which will deal 
with about half-a-dozen Bills, are to hold their first 
meetings at once, the one under the chairmanship of 
Sir L. M‘Iver, the chairman of the other being Mr. 
Seale-Hayne. : ; 
The Bills have already been thoroughly investigated 
by the Select Committees of the House of Lords presided 
over by Lord Windsor and Lord Ribblesdale during 
April and May. These two Committees had much the 
more arduous task, as they had to deal with a larger 
number of Bills, several of which they rejected. It is 
possible, as a result of their work, to form some idea of 
