450 Solar Physics. 



As it is more than probable that there may be considerable 

 errors of division in such a homely affair, it is best to take 

 measures of an object in each of the four quadrants of the 

 circle, as by so doing we, to a great extent, get rid of such 

 error. Neither is it important that the points 0°, 90°, 180°, 

 270°, etc., should correspond to their proper places in the 

 field, as if in the first instance just named, instead of 270°, the 

 index read 140°, we should merely write 140°, 270°, and 

 proceed as before. The angle made by aline joining the two 

 stars, with the line of their motion through the field, is all that 

 is wanted. 



Professional astronomers may smile at the roughness of 

 the contrivance ; but to the amateur to whom expensive 

 appliances are inaccessible, it will be found, when used with 

 care and discretion, to be no mean help in the prosecution of 

 his favourite science. 



SOLAE PHYSICS.* 



The physical constitution of the great centre of our system is a 

 subject of the highest interest, not only to astronomers, but to 

 all cultivators of natural science, and it must command the 

 attention of all educated persons who may not specially devote 

 their minds to scientific pursuits, just in proportion as the 

 results arrived at admit of being placed in a popular form. 

 England, France, and Germany are the three countries specially 

 engaged in this question at the present time. In our own 

 countiy, many private observers, like Messrs. Carrington, 

 Lockyer, JSTasmyth, Howlett, and others, have collected a 

 highly valuable store of facts ; while the Kew Observatory, 

 taking up the previous private labours of Mr. De La Pue, 

 has supplied, for the last two years, as far as the weather 

 would permit, a daily record of the spots or other markings on 

 the sun's surface which photography is able to preserve. In 

 France, M. Chacornac works most industriously at Villc 

 Urbanne, with — we believe — M. FoucauhVs large silvered glass 

 telescope; but the bulletins which he is kind enough to 

 send us do not specify either the instrument or the amount of 

 aperture employed. We have already laid before our readers 

 • 



* Researches on Solar Physics, by Warren De La Rue, Esq., Ph.D., F.R.S., 

 Pres. R.A.S. ; Balfour Stewart, Esq., M.A., F.li.S., Superintendent of the Kew 

 Observatory; and Benjamin Loewy, Esq., Observer and Computer to the Kew 

 Observatory. First Series, on the Nature of Sun-Spots. Printed for private 

 circulation, by Taylor and Francis. 



