Loe ee cet Ce 
Chemistry and Physics. 469 
the result of experiment, that the oscillation of waves may be 
appreciable at a depth equal to 350 times the height of the waves. 
Mr. D that the ripple-like arrangement of 
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clouds may come into the same category with the wind- -ripples 
over dry sands, Hf that if so, the parallel lines of SOn0 yee 
be at right angles to the direction of the wind, 
3. Direct vision Spectroscope of great dispersion. _The disper. 
sion of direct tig vg Hae ade pes Ae s not in general exceed 20° 
from the A line to the Rs line a Ch. V. Zenger r joins to a par- 
tensity “a the light to a great ae ree. The combination of M. 
Brag in a less degree ‘than M. Thollon’s to these re- 
aa aaa the loss by absorption I is claimed to be sma san 
lation for a combination of three prisms. One if risms was 
made of quartz (extraordinary p Mele y another—a iid pt ism 
—was filled pele a mixtare of 4 parts of ether to 6 parts of ben- 
zine. These two prisms were com ohne so as to form a parallale: 
pipedon. The limiting angle of the liquid prism for the line A 
bgp found to be 76°11’. A crown glass prism was then placed 
as to refract the beam of light which passed through the par- 
altelopipeton, The refracting angle of this crown glass prism 
ade 27° 13’. With this arrangement a total dispersion of 
132° 55' was obtained. The total dispersion was equivalent to 
that of thirteen or fourteen bisulphide of (deus prisms of er 
Comptes Rendus, April 9, 1883, pp. oS ¥: 
4. The transmission of power by elec y—An iutoreneiag 
report upon this subject has lately been plein ed to the French 
Academ M. Cornu in behalf of a commission which was ap- 
pointed to examine t e experiment f M. Depretz. A careful 
echaeh of the Aaa of the various experiments is given with 
the following sux 
The work arenes iy the generatrix and guuemucsess to the 
receptrix, increases with the velocity of the generatri 
Depretz ~ succeeded in transmitting Pane four and eciant 
horse power through a resistance 0 160 ohms which r represents a 
double ancraoh line of 8°5*", The work P easetvon was 374 per 
cent of that spent. 
ith a greater velocity of the generatrix it seems possible 
transmit power to greater distances than M. Depretz ne aiaind, 
This amounts to saying that a high electromotive force is neces- 
Sary for this end.— Comptes Rendus, April 9, 1883, pp. ao2-1010, 
5. The esi e. rock-salt at different sarees ar 
Baur by means of a bolometer has studied this question, which 
the researches of Me itoni aud Beene have left undecided. The 
conclusions reached are as follows 
