I1o 
for any reason we required extreme accuracy, was shat- 
tered to pieces (Fig. 1). 
In No. 42 this instrument was externally complete, with 
the exception of a crack in the small unprotected bulb on 
the right limb of the U-tube. The inner shell of the pro- 
tected bulb was broken to pieces (Fig. 2). 
In both of these cases there seems little doubt that the 
damage occurred through the giving way of the unpro- 
tected bulb. In No. 39 the upper part of that bulb was 
ground into coarse powder, and the fragments packed into 
the lower part of the bulb and the top of the tube. The 
large bulb and its covering shell were also broken, but 
into larger pieces, disposed as if the injury had been pro- 
duced by some force acting from within. The thermo- 
meter tube was broken through in three places ; at one 
of these, close to the bend, it was shattered into very 
small fragments. The creosote, the mercury, and bubbles 
of air were irregularly scattered through the tube, and it 
is singular that each of the steel indices had one of the 
discs broken off. The whole took place no doubt instan- 
taneously by the implosion of the small bulb, which at 
the same time burst the large bulb and shattered the 
tube. 
In No. 42 a crack only occurred in the small bulb, 
either through some pre-existing imperfection in the glass 
orfrom the pressure. When the pressure became extreme 
the crack yielded a little, and the sea-water was gradually 
‘NATURE 
forced in, driving the contents of the thermometer before. 
it, and taking it at a disadvantage from within, breaking 
the shell of the large bulb, which was unsupported on 
account of the belt of rarified vapour between it and- 
its outer-shell. The pressure was now equalised within. 
and without the instrument, and the injury went no 
farther. 
mixed up inthe outer case of the large bulb, with the 
debris of the inner bulb, and one of tke steel indices lay 
uninjured across the centre of it. : 
It now becomes an important question why the ther- 
mometer should give way at that particular point, and 
one still more important, how the defect is to be reme- 
died. At first sight it is difficult to imagine why the 
small bulb should give way rather than the outer shell of 
the large one. The surface exposed to pressure is 
smaller, the glass is thicker, and it is somewhat better 
supported from within, as the tube is nearly filled with 
fluid under the pressure of an atmosphere. 
cause must be that the end of the small bulb is the last 
point of the instrument heated and sealed after the tube 
is filled with liquid, and that, consequently, the annealing 
is imperfect at that point. It is evidently of no use to 
protect the small bulb in the same way in which the large 
bulb is protected. The outer shell is merely a precaution 
to prevent the indications being vitiated by the action 
of pressure on the elastic bulb. Against crushing, it is_ 
Fic. 2 3 
no protection ; rather a source of weakness, from its 
greatly increasing the surface. The only plan which 
seems to be feasible is to thicken the small bulb itself, and, 
if possible, to improve its temper. It is only fair to say 
that these thermometers were tested and guaranteed to 
only three tons on the square inch, and that the pressure 
to which they were subjected was equal to four tons, 
WYVILLE THOMSON 
NOTES 
Tue Albert Gold Medal of the Society of Arts has this year 
been awarded to M. Chevreul, Member of the Institute of France, 
and Director of the Gobelins and of the Jardin des Plantes at 
Paris, for his valuable researches in connection with Saponifica- 
tion, Dyeing, Agriculture, and Natural History, which, for 
more than half a century, have exercised a wide influence on the 
industrial arts of the world. 
Pror. MuMPHRY announces that the Cambridge class for 
Practical Histology will meet during the months of July and 
August at the Anatomical Museum on Tuesdays, Thursdays, 
and Saturdays, at 9 A.M., commencing July 1. The Class for 
IIuman Osteology will meet on Mondays, Wednesdays, and 
Tvidays at the Anatomical Museum at 9 A.M. during July and 
August, commencing July 2, The. Professor of Zoology and 
Comparative Anatomy (Mr. Newton) announces that a class for 
practical work will be carried on in July and August by the 
Demonstrator in Comparative Anatomy, commencing July 2. 
The fee for the course will be one guinea. 
THE fcllowing gen lemen have been recommended by the 
French Academy of Sciences to the Minister of Public Instruc- 
tion for the four vacant posts in the Bureau des Longitudes :— 
M. Serret, M. Mouchez, M. Perrier, and M. Janssen. 
THE Council of the Society of Arts haying been informed 
that Her Majesty’s Commissioners do not intend to publish re- 
ports on the different departments of the exhibition of the present 
year, have decided to undertake that duty, and for this purpose 
have engaged the services of gentlemen specially skilled in the 
subjects of the several sections, to prepare such reports for pub- 
lication in the Society’s Fournal, A report on Ancient Objects, 
by Mr. C, Drury Fortnum, F.S.A., and another on Surgical In- 
struments and Appliances, by Mr. R. Brudenell Carter, F.R.C.S., 
| appear in the Yournal for May 30. ’ 
Ar a meeting of the Council of the Leeds Naturalists’ Field 
Club and Scientific Association, three of its members—Mr. Wim. 
Todd (vice-president), Mr. W. D. Roebuck (secretary), and Mr. 
John W. Taylor—were appointed a sub-committee to consider 
| the best manner of collecting information for a series of cata- 
logues of the natural productions of the district. The sub-com- 
mittee having taken into consideration all the facts bearing upon 
the subject in hand, are of opinion that jthe following procedure © 
should be adopted :—1. That in view of the approaching meet- 
ing in Bradford, in August next, of the British Association for 
the Advancement of Science, it is advisable that there should be 
produced by this society, and under its auspices, a brief account 
of the present state of our knowledge of the fauna, flora, and. 
geolozical and topozraphical features of the district. 
for present use the most convenient district to illustrate would 
Alcohol, creosote, mercury, and sea-water were 
2. That 
I believe the © 
