AUGUST 27, 1914] 
NATURE 
671 
Sons and Co., Ltd., of Kilmarnock, and supplied to 
the Admiralty for service at one of the explosive 
depéts, where the question of absolute safety from 
fire is of the first importance. The locomotive has 
a reservoir partly filled with water, and is charged 
with high-pressure steam from a boiler placed outside 
the danger zone. It can work on one charge of the 
reservoir for several hours on continuous hauling, or 
for a much longer time on ordinary shunting work. 
It can stand for twelve hours in ordinary open-air 
temperature with small loss of steam, and can run 
back to the charging station under the very low 
pressure of 15 lb. per square inch. All the test con- 
ditions were more than fulfilled at the trials. The 
engine is not only fireless, but the rubbing surfaces, 
such as the brake blocks, and the impact points, such 
as the buffers, have been rendered sparkless by the use 
of special facings. 
Tue lack of supplies of glass and porcelain from 
Germany and Austria, on account of the war, has 
affected various businesses depending upon them. We 
are informed, however, by the Thermal Syndicate, 
Ltd., manufacturers of pure fused silica, that it is 
still in a position to supply its ‘ Vitreosil’’ ware 
promptly, as this substitute for porcelain and glass is 
made entirely in the works of the syndicate at Wall- 
send-on-Tyne. 
“THE Report of the Fourteenth Meeting of the 
Australasian Association for the Advancement of 
Science ’’ has been recently issued by the Associa- 
tion from its permanent office in Sydney. It is 
edited by Dr. T. S. Hall, and contains a full account 
of the proceedings of the meeting held at Melbourne 
in 1913. 
OUR ASTRONOMICAL COLUMN. 
Comet 1913f (DELAvAN).—Little news is at hand 
concerning observations of Delavan’s comet. During 
the present week the object will be situated in the 
constellation of the Lynx pursuing a course nearly 
midway between the stars 27 and 31 in that con- 
stellation, and at right angles to a line joining 
these two stars. The small chart below, given pre- 
viously in this column on August 13, is reproduced 
here again for reference :— 
Mr. . W. 
5B. slripp, 
August 22, says that he observed the comet on the 
writing from Isleworth on 
night of August 21 with a binocular field-glass. He 
describes it as of “substantial proportions promising 
to be a fine object later.”’ 
THe LarGe CaNaDIAN REFLECTOR.—The Journal of 
the Royal Astronomical Society of Canada for May- 
NO. 2339, VOL. 93| 
June (vol. viii., No. 3) contains two illustrated articles 
dealing with the proposed site and the observing con- 
ditions for the large 72-in. reflector; these are con- 
tributed by Messrs. W. E. Harper and J. S. Plaskett. 
An examination of the seeing conditions of many 
scattered regions has resulted in the choice of a hill, 
Little Saanich, 732 ft. high, situated seven and a half 
miles from Victoria. While Mr. Harper admits that 
the transparency of the air at the Lick Observatory is 
superior to any place examined by him in Canada, he 
holds the opinion that in the matter of low temperature 
range and the character of the seeing itself conditions 
may be looked for to equal those upon Mount Hamil- 
ton. The Government of British Columbia has con- 
sidered the whole project in a broad-minded way and 
agreed to provide 10,000 dollars for the purchase of 
the land and to build a road to the summit of the hill. 
Fifty acres of land have been secured. As regards the 
instrument itself, the disc for the mirror is ready for 
shipment, and it is stated that there is every prospect 
of the telescope being ready for erection next year. 
Messrs. Warner and Swasey are the constructors, and 
Mr. Plaskett says that he is in the highest degree 
delighted with their work, and firmly convinced that 
“this telescope in rigidity, suitability, and convenience 
will be away ahead of any hitherto built.” 
Rapip CONVECTION IN STELLAR ATMOSPHERES.—In 
this column for April 30 of this year (vol. xciii., p. 224) 
reference was made to the new interpretation to the 
observed displacements of the solar lines suggested by 
Mr. Evershed. The observations were explained by a 
very rapid descent of the cooler gases and vapours 
upon the body of the sun, most rapid in the higher 
levels, and less rapid as the successively lower levels 
were reached, combined with small effects due to 
pressures less than one atmosphere. Prof. W. W. 
Campbell points out (Lick Observatory Bulletin, 
No, 257) that these observations give us apparently a 
measure of the general convectional circulation in the 
sun’s atmosphere, which, if confirmed, ‘‘must be con- 
sidered as of very great importance.’”’ These con- 
siderations lead him to inquire into what may be 
occurring in the atmosphere of other suns. Assuming 
that surface temperatures of stars must be largely a 
function of their convection-activity, a sluggish star, 
i.e. One with little convection, should have a relatively 
cool surface, while a massive star, approximating to a 
perfect gas, should have a large convection and have 
relatively a hot surface. Having found that the radial 
velocities of Class B stars are observed about 4-5 km. 
a second too great (then attributed to pressure in the 
absorbing layers), Prof. Campbell, in the light of 
Evershed’s results as regards the solar atmosphere, 
puts forward the view that this excess is probably due 
to the existence of relatively unobstructed radial circu- 
lation. This circulation would bring the internal heat 
to the surface, with little loss of time, to replenish 
loss by radiations to surrounding space. If the sun’s 
atmosphere, which is sluggish, can account for a speed 
of 1 km. a second, a relatively hot star like those of 
Class B might rationally have a velocity of 4-5 km. a 
| second. 
A NoOveEt COMBINATION OF INSTRUMENTS.—Dr. Frank 
Schlesinger in the Publications of the Allegheny 
| Observatory (vol. iii., No. 13), gives an account of the 
solar spectrograph of that observatory and the vertical 
telescope with which it is used. These instruments 
are the gift of the Hon. H. Kirke Porter, and they 
form part of the Keeler memorial telescope. The 
Keeler memorial telescope is a 30-in. reflector, and its 
mounting is used not only as a polar heliostat carrying 
an 18-in. mirror, but as a coelostat also with an 18-in. 
mirror. The telescope is mounted on a tall pillar cir- 
cular at its upper end, and the dome is raised corre- 
