DESIDERATA, ETC. 
XXI 
That Mr. Baily, Mr. Davies Gilbert, Mr. Lubbock, and the 
Rev. G. Peacock, be a Committee to make the required represen¬ 
tation to the Government, and to solicit the cooperation of the 
French Institute. 
4. That the East India Company be requested to further the 
same objects, especially at their establishment at Madras. 
5. That M. Arago be respectfully requested to publish, and 
to have reduced, his valuable and extensive collection of Mag- 
netical Observations made at the Observatory at Paris. 
6. That a representation be made to Government of the im¬ 
portance of sending an expedition into the Antarctic regions, for 
the purpose of making observations and discoveries in various 
branches of Science, as Geography, Hydrography, Natural Hi¬ 
story, and especially Magnetism, with a view to determine pre¬ 
cisely the place of the Southern Magnetic Pole or Poles, and 
the direction and inclination of the magnetic force in those re¬ 
gions. 
7. That a further examination of the Electro-magnetic con¬ 
dition of mineral veins be recommended. 
Desiderata noticed in Professor Christie's Report. 
1. A regular series of observations conducted in this country 
on the diurnal variation of the needle. 
2. To ascertain how far the method of e torsion’ is applicable 
to determine the diurnal variation of the horizontal magnetic 
force. ( Reports , vol. ii. p. 119.) 
3. To ascertain experimentally the direction of electrical cur¬ 
rents occasioned in a large sphere of copper filled with bismuth, 
heated at the equator, and cooled at the poles, with a view to the 
theory of the origin of the earth’s magnetic polarity. ( Reports , 
vol. ii. p. 132.) 
t 
RADIANT HEAT. 
Desiderata reported by Professor PowelL 
1. The accurate verification of Sir J. Leslie’s observation that 
the focus for simple heat , in concave reflectors, is nearer to the 
reflector than that for light. ( Leslie on Heat , p. 14.) 
2. The proportion of heat reflected at different incidences. 
3. Whether radiation takes place in an absolute vacuum. 
4. Whether heat is radiated from hot bodies in liquid media, 
and whether it is reflected , &c., and has the same relations to 
surfaces as in air. 
