the base :—13, 35, 67, 95, 148°5, 176'5, 208°5, 230°5 
millimetres. The height of the cylinder was determined 
_ from the ascertained mean distance of the corresponding 
37 points of intersection of the lines on the upper and 
_ lower surfaces, including the centres. The diameter of 
. the cylinder was determined from the ascertained mean 
_ length of the 48 diameters, included between the 
_ Corresponding points of intersection on its cylindrical 
portion. 
_ The measurement was effected by means of an ap- 
_ paratus specially constructed for the purpose by Fortin, 
and it indicated minute differences of length of zz, line, 
_ Orz755 mm,. The standard measures used for determin- 
_ ing the absolute length measured were 16 brass measures 
specially constructed for the purpose, each very nearly 
_ equivalent to the height of the cylinder, and 16 other 
_ measures, each nearly equivalent to its diameter. The 
length of each of these two series of measures in relation 
to each other was ascertained by numerous observa- 
tions with the new apparatus ; and the total length of each 
set of 16 measures in relation to the new standard unit 
was obtained by comparing the sum of their length 
with Borda’s végle of 2 toises, No.1, to which they 
very nearly corresponded in length, by means of the 
comparateur used for the comparison of these large 
“measuring rules. 
_ The final result of the measuring operations was that 
_ the mean height of the cylinder was determined to be 
2°437672 decimetres, and its mean diameter 2'428368 
decimeters, at the temperature of 17°6 C, According 
to Borda’s determination of the coefficient of the linear 
expansion of brass, the volume of the cylinder was deter- 
mined by computation to be nearly 11°28 cubic decimetres, 
when at the temperature of melting ice. 
For ascertaining the weight of water displaced by this 
cylinder, a series of brass weights was specially con- 
structed, consisting of a unit or provisional kilogram, 
made as nearly as possible of the estimated weight of a 
cubic decimetre of water, together with 11 exact copies 
and smaller weights in decimal subdivision down to the 
millionth part, all carefully verified and deemed to be ac- 
curate within less than half of one-millionth part. 
The mean weight of the cylinder in ordinary air was 
taken, no reduction to a vacuum being deemed requisite, 
the interior of which communicated with the external air. 
For this purpose a metallic tube, 1'285 mm. in diameter, 
was screwed to the top of the cylinder, its end being out 
of the water when the cylinder was immersed. The top 
of the cylinder was 43 mm. from the surface of the water 
during the weighings, and the volume of the tube im- 
mersed was therefore 55°77 cubic mm. Taking the volume 
of the cylinder to be 11°28 cubic decimetres, the volume 
of the metallic part of the cylinder was computed to be 
- 4°506 cub, decim., and of the hollow part filled with air 
9'774. cub. decim. During the weighings the cylinder was 
surrounded with ice, but the temperature of the water was 
never below o°2 C, and the mean temperature was 0°'3. 
aa final results of the weighings were declared to be as 
llows :— 
Prov, kilo. 
Weight of the cylinder in air, in terms of 
the unitemployed. . . . . = 11'4660055 
Its mean weight in distilled water, after de- 
ducting the weight of air in the cylinder, 
and of the air displaced by the weights 
SIE EY SS + = 01967668 
Hence weight of the volume of distilled 
water equal to the volume of the cylinder = 11°2692387 
H, W. CHISHOLM 
(To be continued.) 
NATURE 
1 
_ drawn around the cylinder at the following distances from 
as the weights used were of similar metal to the cylinder, | 
389 
NOTES 
Ir is announced that the Transatlantic Balloon will leave New 
York to-day. It will carry four passengers—Prof. Wise and 
Mr. Donaldson, the aéronauts ; an officer of the United States 
Signal Service, and an agent of the Daily Graphic. They hope 
to reach some point on the English or Continental coast in about 
sixty hours from their departure from New York. They have 
with them six very powerful and experienced carrier-pigeons, pur- 
chased in Belgium, which, if liberated from the balloon within 
‘*pigeon flight ” of the coast, are expected to fly directly to their 
old homes. Each of these has painted on his breast, in indelible 
ink, the outline of a balloon, and on his wings the words, ‘‘ Send 
news attached to the nearest newspaper.” Despatches received 
by these pigeons should be sent to the nearest newspaper for 
publication. We wish these daring men a safe landing ; but 
while we do this we regard the enterprise as one needlessly 
hazardous, so far as the settlement of the scientific problem is 
concerned. 
Mr. CAMPBELL, the Chief Secretary of the Inspectorate- 
General of Customs in China, is now in Europe with a view of 
obtaining instruments for a complete chain of meteorological 
stations in that country. It is also proposed to transmit weather 
information all along the east coast of Asia. This is great news, 
and we shall return to this important matter, giwing full details of 
the proposals, 
Miss ELIZABETH THOMPSON, of New York, has made a 
donation to the American Association for the Advancement of 
Science of 1,000 dols., for the purpose of advancing scientific 
original research ; and she intends repeating the donation annu- 
ally during her life. 
M. STEPHAN has succeeded in finding Faye’s Comet. 
correction of the Jahrbuch Ephemeris is almost z:/, 
The 
Mr. FRoupE, who is now with the Devastation, informs 
us that it is Mr. W. Barlow, not himself, who is president of 
Section G at the ensuing meeting of the British Association, 
Mr. Froude{will, indeed, probably not even be able to attend 
the Bradford meeting at all. 
WE learn from the Afonthly Microscopical Fournal that Prof. 
Gegenbauer, of Jena, the well-known comparative anatomist, 
has been nominated Professor of Anatomy and Director of the 
Anatomical Institute in the University of Heidelberg. 
THE arrangement made by Prof. Henry, of the Smithsonian 
Institution, a few months ago, for the interchange between 
America and Europe, by Atlantic cable, of important astrono- 
mical discoveries and announcements, appears to have borne ex- 
cellent fruit. One great object of this movement was to enable 
astronomers in all parts of the world to concentrate attention 
upon any celestial phenomenon before too great a change of 
place had occurred, or before the intervention of a long period 
of moonlight after the first discovery. On the 26th of May last Prof. 
Henry announced a new planet, discovered by Prof. Peters, to 
the Observatory of Paris, among other institutions, and on the 
following night it was looked for by the director of the Observa- 
tory of Marseilles, who at once detected it, and subjected it to a 
careful criticism, The announcement of three planets has thus 
far been made from the Smithsonian Institution to Europe ; the 
only return communication being that of a telescopic comet, dis- 
covered at Vienna on July 5. On being notified of the fact, Prof. 
Hough, of the Dudley Observatory at Albany, made search for 
it, and succeeded in finding the object without any difficulty. 
BIoLoey is flourishing at the Antipodes. The last mail has 
brought us ‘‘ Australian Vertebrata, fossil and recent,” by G, 
Krefft, curator and secretary of the Australian Museum, Sidney ; a 
list of Australian Longicorns, chiefly described and arranged by 
Francis P. Pascoe, with additional remarks by George Masters, 
assistant curator of the Australian Museum; Guide to the 
