May 16, 1912] 
NATURE 273 
the moist air within it is cooled sufficiently to make 
water condense on any ions which may be present, | 
no appreciable stirring of the air resulting from the 
expansion. 
Ionising particles passing through the | 
air leave visible trails, consisting of cloud particles | 
condensed on the ions. 
Cuemistry.—Sir W. Crookes, O.M.: Properties of 
pure fused boron, and the volatility of metals of the 
platinum group. Pure fused boron, prepared by Dr. | 
Weintraub by decomposing a volatile boron com- | 
pound in the electric arc, is deposited on water-cooled 
copper electrodes. 
denses in a crystalline form. 
fused in a mercury are furnace. 
easily scratches quartz and corundum. 
remarkable property of pure fused boron 
abnormal value of its 
resistance. Between ordinary room temperature and 
a dull red heat the resistance drops in the ratio of 
2x 10° tows 
in series with an electric lamp, at room temperature, 
obstructs nearly all the current. Warming the boron 
reduces the resistance, and the lamp lights. 
Platinum, in the form of very thin ribbon, heated for 
many hours to a temperature approaching its melt- 
ing point, sublimes and deposits beautifully formed 
crystals on the surrounding vessel. Iridium is more 
volatile than platinum at a high temperature. A 
plate of pure iridium, after having been heated for 
twenty-two hours, at 1300° C., has a_ beautiful 
‘““moirée” surface. A crucible of iridium, showing 
signs of crumbling after long heating, was exhibited. 
Messrs. Carl Zeiss (London), Ltd.: Apparatus for 
demonstrating liquid crystals with polarised light 
(projection on screen). This instrument consists of 
an automatic feeding arc lamp of 5 amperes, con- 
densing lenses, water cooler, mounted on optical 
bench, a microscope, with specially wide body tube 
situated on the end of optical bench in upright posi- 
tion, and provided with a blow-pipe arrangement and 
air blast for the purpose of heating chemical pre- 
parations to a temperature up to 800° C. Analyser 
and objectives are provided with cooling chambers, 
and the object stage is arranged with 
terminals for passing a current across the stage. A 
specially constructed polariser is fitted below the 
object stage possessing a large aperture as compared 
with its length. 
ENGINEERING.—Mr. J]. Dewrance: An _ adhesion 
pump. A viscous fluid enters by gravity a shallow 
spiral channel cut on a revolving surface that is held 
against the smooth surface of a corresponding 
chamber. 
progresses along the channel and is delivered at the 
other end at considerable pressure. 
Pure boron can be 
It is very hard, and 
is the 
The agglomerated boron con- | 
The most | 
A small piece of fused boron mounted | 
electric | 
Motor-gyrostats are mounted in various ways within 
wooden boxes. By operating the gyrostats by means 
of electromagnets, the boxes, which are provided 
with arms and legs, are caused to walk on the floor 
and to walk arm over arm along wires stretched 
horizontally. 
NOTES. 
Ar a meeting of the London Section of the 
Deutsche Kolonial-Gesellschaft on May 11, Dr. A. 
Smith Woodward gave an address on the significance 
of the recent discoveries of Cretaceous Dinosauria in 
German East Africa. Since 1909 excavations have 
temperature coefficient of | been in progress in the Tendaguru Hills, under the 
immediate supervision of Prof. W. Janensch and Dr. 
E. Hennig, and an appeal is now being made for 
funds to proceed with a fourth year’s work. In 
describing the results, so far as he had seen them in 
the Berlin Museum, Dr. Woodward emphasised the 
importance of an exhaustive comparison of the 
sauropodous dinosaurs of Africa with those of North 
America, which would now soon be possible. He 
also alluded to the problems suggested by the gigantic 
size of some species, which much exceeded the 
extreme limit of growth calculated to be possible by 
the late Prof. Marsh when he first discovered the 
femur of Atlantosaurus. Prof. W. Branca sent for 
exhibition to the meeting a plaster cast of the 
humerus of Gigantosaurus, 2:10 metres in length, 
which is shortly to be placed in the British Museum 
(Natural History); while Prof. Janensch lent an 
important series of photographs which he had taken 
at different stages during the excavations. The 
German society is to be congratulated on its 
enlightened interest in purely scientific work under- 
taken in a colonial possession, and English science 
will appreciate the compliment paid to one of its 
exponents by his being invited to deliver the address 
in question. 
Pror. FrRUHLING, who died at Brunswick on April 
24, at seventy-one years of age, did much towards 
enabling young men engaged in practical sugar work 
| to obtain a scientific training. After graduating in 
The fluid adheres to both surfaces, and | 
1866 with a thesis on the nitric acid contents of 
agricultural crops during the various periods of their 
| growth, he started, in 1870, a public analytical labora- 
Prof. E. G. Coker: Special polariscope for examin- | 
ing engineering models under stress. The polari- 
scope is constructed for examining long transparent 
models of engineering structures by circularly 
polarised light. Plane polarised light, obtained by 
reflection from a black glass plate, is afterwards 
circularly polarised by large quarter-wave plates of 
mica. The object under stress is viewed through an 
analyser constructed of glass sheets, and a model, 
40 in. by 10 in., can be viewed at one time without 
the aid of Nicol’s prisms. 
Dr. J. G. Gray and Mr. G. Burnside: (1) Con- 
tinuous-current motor-gyrostats for the demonstration 
of the properties and practical applications of the 
gyrostat. The gyrostats, which are motors of the 
Gramme Ring type, are provided with accessories for 
demonstrating the properties and practical applica- | 
tions of the gyrostat. Experiments (both qualitative 
and quantitative) can be carried out with convenience 
and precision. (2) Walking and climbing gyrostats. 
NO, 2220, VoL. 89| 
tory, and two years later added a department at which 
instruction in sugar work was given. This ‘Schule 
fiir Zucker-Industrie zu Braunschweig ”’ has flourished 
ever since, and been attended by students from prac- 
tically every sugar-producing country in the world, 
among them being fourteen Englishmen. His 
‘“Anleitung,”’ or methods of analysis for all products 
connected with the sugar industry, has been trans- 
lated into several foreign languages; in 1911 it 
reached its seventh edition. He also published an 
“Anleitung,” or laboratory guide, for soil analysis, 
and edited Stammer’s pocket calendar for sugar manu- 
facturers since 1894. The majority of sugar factories 
in the north of Germany retained him as their official 
analyst. He also invented several useful pieces of 
apparatus, which have been adopted for sugar work 
in a large number of Continental sugar laboratories. 
