7 
} 
, 

Oct. 5, 1871] 
NATURE 
447 

forming the connecting link of a sentence must have been 
dropped. What I intended to say, without the slightest notion 
of giving a ‘‘technical or scientific” opinion, was, ‘‘ The iron is 
alloyed ix crucibles, formed with certain clays and a preparation 
of plumbago.” The words italicised disappeared in some mys- 
terious way. The next of my idiotic sentences goes on to talk 
about the crucibles, or ‘‘crveusets,” as, to the great scandal of 
Mr. Forbes, I ventured to call them. If I could stop here, an 
humble apology for my fault might, perhaps, serve my purpose, 
but, alas! I have more to answer for. Vaguely dreaming of the 
foot-pound, I actually zwrote kilometre for kilogyammetre, when 
_ speaking of the power of the new steam hammer ; and, worst of 
all, I also WROTE ‘‘ Sheffield Gun Metal.” 
Can I ever hope to be forgiven when thus I write myself 
down an ass? MEDICus 
P.S. —As to the question whether Krupp invented the process 
employed at his factory, I offer no opinion “scientific” or 
ordinary, I only repeat the impression which prevails. 


| © \ FURTHER NOTES ON CERATODUS 
INCE the article on Ceratodus (published in NATURE, 
Nos. 99 and 100), was written I have examined a 
mature female, transmitted, with other examples, by the 
Trustees of the Sydney Museum tothe National Collection, 
and am enabled to make the following additions :— 
1. The oviduct in its developed conditions is, with re- 
gard to its internal structure, surprisingly similar to that 
of Menopoma. 
2. The ova are expelled through the oviduct, and not 
through the peritoneal slits ; they receive in the oviduct a 
coating of an albuminous substance as in Batrachians. 
3. The caudal termination of the vertebral column is 
subject to individual variation. In one example the neural 
and hzemal elements are continued far beyond the noto- 
chord, and are confluent into a tapering band, which is 
segmented, as is the case in some specimens of Dzpferus 
or Crenodus. ALBERT GUNTHER 

ON THE BENDING OF GLACIER ICE * 
R. MATTHEWS and Mr. Froude had supported long 
rectangles of ordinary ice at the two ends, weighted 
them in the centre, and thus caused them to bend. The 
ice employed, if I recollect right, was of a temperature 
some degrees below the freezing point, andin my little Alpine 
book recently published I expressed a hope that similar 
experiments might be made with glacier ice. I have been 
trying my hand at such experiments. The ice first em- 
ployed was from the end of the Morteratsch Glacier, and 
when cut appeared clear and continuous. A little expo- 
sure, however, showed it to be disintegrated, being com- 
posed of those curious jointed polyhedra into which 
glacier ice generally resolves itself when yielding to 
warmth. Still, when properly supported and weighted, 
a long stout rectangle of such ice showed, after twelve 
hours, signs of bending. 
I afterwards resorted to the ice of the sand cones, which, 
as you know, is unusually firm. From it rectangles were 
taken from three to four feet long, about six inches wide, 
and four inches deep. Supported and weighted for a 
considerable time, no satisfactory evidence of bending 
appeared ;| the bars broke before any decided bending 
took place. Smaller bars were then employed. Two 
of these were placed across the mouth of an open 
square box, their ends being supported by the sides of the 
box. They formed a cross, and a clear interval of at least 
an eighth of an inch existed between them where they 
crossed. The upper one was carefully weighted with a 
block of ice; after two hours it had sunk down, and 
* The following is an extract from a note addressed to Prof. Hirst, and 
sent from Pontresina in the hope that it would reach Edinburgh in sufficient 
time to be communicated to Section A of the British Association. It was a 
few hours too late.—J, T. 

was found frozen to the under one. They were then 
separated, and one of them was allowed to remain sup- 
ported at the ends and weighted by ice at the middle. In 
afew hours it had bent into a curve, the versed sine 
of which from a chord uniting the two ends was, at least, 
two inches. In fact, when the rectangles are thin, and 
the weight carefully laid on, flexure commences very soon, 
and may by cautious manipulation be rendered very con- 
siderable. I think Mr. Froude told me that in his 
experiment the molecules were “in torture,’ and that 
they in great part recovered their positions when the 
weight was removed. In the foregoing experiments the 
flexure was permanent. 
I tried to bend the rectangle just referred to back again 
by reversing its position and weighting it with the same 
block of ice. But whether owing to my want of delicacy 
in putting on the weight, or through the intrinsic brittleness 
of the substance itself, it snapped sharply asunder. 
I left in your hands when quitting London an exceed- 
ingly interesting paper by Prof. Bianconi, in which are 
figured the results of various experiments on the bending 
of, I think, lake ice. The foregoing experiments on 
glacier ice confirm his results. 
August 4 JOHN TYNDALL 
I may add that various experiments were subsequently 
made, and a means discovered of rendering the bending 
very speedily visible. I hope before long to return to the 
subject.—J. T., September 28 

THE MIGRATION OF QUAIL 
dpe fact of this little bird having visited England 
this year in such numbers appears to have attracted 
the attention of naturalists as well as sportsmen. In the 
columns of the /7e/d may be found a census giving parti- 
culars of this migration. And it will appear a curious 
coincidence when I mention that there has been here a 
greater migration of quail this year than ever remembered 
before. Where they conie from is somewhat mysterious. 
They have been shot in hundreds in some paddocks, and 
found as numerous as ever in ten days. I can only 
account for it by stating that it has been a most remark- 
able year for grass, and consequently cover was good ; and 
this does not appear conclusive, for the grass has been 
good all over the country for hundreds of miles towards 
the north, from which direction some appear to think they 
come. They are found generally in paddocks, where 
thistles grow. Can there be any common cause affecting 
these facts ? 
Melbourne, August 10 AUSTRAL-ALPINE 

FARDIN DESSAI, ALGER 
i 1832 the then French Government conceived the 
idea of forming near the town of Algiers a botanical 
garden, in which all plants likely to be easily grown in 
Algeria, and which might be useful either for their orna- 
mentation, or from their economic value, should be kept 
for distribution or for sale. A portion of ground situated 
between the sea and the public road, and occupying the 
place of an old ama or marsh, was selected for this 
purpose, which is about two miles from the town. In 1867 
the Emperor of the French conceded this establishment 
to the “Société Générale Algérienne,” under whose 
auspices, but under the direct superintendence of M. 
Auguste Riviére, the gardens at present are. 
In addition to the level swamp, the gardens now also 
occupy the slope of a low hill on the opposite side of the 
road. The level ground is laid out in alleys which open 
out into a circular boulevard which surrounds the whole 
garden. Carriages are admitted to the circular drive only, 
foot passengers to the cross walks. A stream of fresh 
water runs through the grounds, forming in one place a 
small lake. 
