x “tt 
JuNE 30, 1923] 
NATURE 
993 

that when the pivoted system is upright the track 
is horizontal. One, two, or more balls rotate on 
the track, each controlled by a pusher and a check 
carried by a member which rotates slowly (about 
12 revolutions per minute) in the direction of spin 
of the gyroscope. When the system is upright the 
balls move round the track in contact with their 
pushers, and form a balanced system. When the 
system is inclined to the vertical the track is inclined 
to the horizontal, and each ball when ascending the 
slope of the track rests against its pusher, but after 
crossing the crest of the slope it is accelerated down 
the track and rests against its check. The motion 
of the balls relative to the pushers and checks results 
in the application to the pivoted system of an 
integral erecting couple. Such instruments possess 
an accuracy, for bombing purposes, amounting to 
one-eighth or one-tenth of a degree, or about 20 feet 
on the ground from a height of 12,000 feet. Later 
forms of Gray stabiliser set themselves into the true 
vertical even when the vehicles on which they are 
mounted are turning, and this holds for all speeds 
of turning. This result is obtained by constructing 
the apparatus so that a horizontal component of 
spin lies across the pivoted system, which is mounted 
so as to be pendulous with respect to the pivots. 
The direction of the horizontal spin, and its amount, 
are arranged so that when the vehicle turns there 
comes into existence a gyroscopic couple, applied 
about the fore and aft pivots, which is exactly equal 
and opposite to the so-called centrifugal couple 
applied to the pivoted system. Both couples are 
proportional to the angular speed at which the 
vehicle turns, and both change sign with that of 
the turning motion. 
_Zoological Society, June 12.—Sir S. F. Harmer, 
vice-president, in the chair.—N. A. Mackintosh: 
The chondrocranium of the teleostean fish Sebastes 
marinus.—R. I. Pocock: The external characters of 
the pigmy hippopotamus (Ch@ropsis liberiensis) and 
of the Suide and Camelide—E. E. Austen: A 
revision of the family Pantophthalmide (Diptera), 
with descriptions of new species and a new genus. 
—Raymond Dart and C. W. Andrews: The brain 
of the Zeuglodontide (Cetacea), with a note on the 
skulls from which the endocranial casts were taken, 
—R. Broom: On the structure of the skull in the 
carnivorous dinocephalian reptiles.—Oldfield Thomas 
and M. A. C. Hinton: On mammals collected by 
Capt. Shortridge during the Percy Sladen and 
Kaffrarian Expedition to Orange River. 
Paris. 
_ Academy of Sciences, June 4.—M. Albin Haller 
in the chair.—Charles Richet: The function of the 
spleen in nutrition. An account of some feeding 
experiments on dogs after removal of the spleen.— 
Gabriel Bertrand and Mlle. S. Benoist: A new sugar, 
procellose. Filter paper is converted into cellulose 
octacetate by the method of Maquenne and Goodwin, 
and the mother liquors from the crystallisation of 
this acetate worked up for the isolation of the new 
sugar, to which the name procellose is given. Its 
composition is C,sH;,0,, and rotation [a], = +22°-8 
at 21° C.; its reducing power is half that of glucose. 
Its probable formula is given.—C. Guichard: Two 
triple orthogonal systems which correspond in such 
a manner that the first tangents to the two systems 
are reciprocal polars with respect to a linear complex. 
—Sir Richard Hadfield was elected corresponding 
member for the section of chemistry in succession 
to M. Paterno, elected foreign associate-—René 
Maire was elected corresponding member for the 
section of botany in succession to the late M. 
NO. 2800, VOL. I11] 
_Battandier.—Jules Drach: 
Remarkable classes of 
W congruences.—Bertrand Gambier: The curves of 
Bertrand, and in particular, those which are 
algebraical—MM. Schouten and Struik: A theorem 
of conformal transformation in differential geometry 
of » dimensions.—M. Lainé: The integration of 
differential equations.—Serge Bernstein: A property 
of integral functions.—Henri Eyraud: Multiple 
spaces and tensors.—M. Chatillon: The para- 
magnetism of cobalt sulphate in aqueous solution. 
An explanation of the divergent results of Cabrera 
and Triimpler on the coefficient of magnetisation 
of cobalt salts. With solutions prepared at ordinary 
temperatures, the results are independent of the 
concentration, but if the solutions are prepared hot 
and allowed to cool to the ordinary temperature, 
the atomic moment is a function of the concentration. 
—M. de Broglie and A. Lepape: The K absorption 
discontinuity of krypton and xenon. Krypton gave 
N =36 (\ =0-8648A) and xenon N =54 (A =0:3588A). 
The last figure is approximate only.—L. Bull: A 
photographic technique for detecting minute deforma- 
tions in rectilinear objects.—Adolphe Lepape: The 
quantitative measurement of radium emanation 
by the a-radiation. Corrections due to pressure 
and to the nature of the gaseous mixture. Correc- 
tions, generally neglected, should be applied to 
measurements of radium emanation: their import- 
ance depends not only on the variations of density 
and composition of the gas present in the condenser, 
but also on the dimensions of the latter.—Jean 
Barbaudy: The removal of toluene by steam.— 
A. Boutaric and Mlle. Y. Nabot: The influence of 
a third substance on the miscibility of phenol and 
water.—Marcus Brutzkuo: A contribution to the 
theory of internal combustion motors. Some 
theoretical considerations of the combustion of 
gases and liquids in engine cylinders derived from 
the application of the law of mass action.—Henri 
Guinot: A continuous method of dehydrating 
alcohol and certain organic liquids. A modification 
of the Young method for dehydrating alcohol, in 
which the benzene proposed by Young is replaced 
by trichlorethylene. The distillate separates into 
two layers, the lower layer containing only 2 per cent. 
of water and practically the whole (99 per cent.) 
of the trichlorethylene. This is returned to the still. 
—P. Brenans and C. Prost: The iodosalicylic acids. 
The 1.2.3 andr. 2.5 mono-iodide acids have been 
prepared, starting with aminosalicylic acids of known 
constitution: each of these has been transformed 
into the same 1.2.3.5 di-iodosalicylic acid.—A. 
Blanchetiére: The action of dry heat on the alkaline 
earth salts of the carbamine acids.—L. Cayeux: 
The réle of the crinoids in the history of the second- 
ary oolitic iron minerals. The contribution of the 
remains of crinoids to the constitution of the oolitic 
iron minerals of the secondary epoch is of great 
importance.—Pierre Bonnet: The Neocretacian of 
Daralagoez (southern Transcaucasia).—P. H. Fritel : 
Two species of ferns new to the fossil flora of the 
millstone grit of Beauce (Aquitanian).—M. Gruvel : 
Some coral deposits on the western coast of Morocco. 
—L. Eblé: Magnetic measurements in the Paris 
basin. The values of the magnetic elements cal- 
culated to January 1, 1922, are given for 40 stations, 
ten of which are new.—R. de Montessus de Ballore : 
The methodical prediction of the weather. The 
results of a study of statistics given by Louis Besson 
in 1905.—J. Riviére: The variation of nocturnal 
temperature with a clear sky.—G. Reboul: The 
acoustic opacity of banks of clouds: application 
to the rapid determination of the thickness of a 
cloud layer.—Maurice Lenoir : The nucleolar material 



