1870.] 



Presents. 



165 



that the star Arcturus does give us more heat than aLvroe, — a result probably 

 due to the same cause which gives rise to the difference in colour between 

 these stars, viz. the greater absorption of the red end of the spectrum in the 

 case of aLyrae than in the case of Arcturus. 



I may here mention that on June 25, 1S69, I made a direct comparison 

 between Arcturus and aLyne. The result gave for the heat received from 

 Arcturus : that from a Ljrse : : 3 : 2 ; but on account of the observations of 

 a Lyree having been interrupted by cloud, they were not sufficiently 

 numerous to eliminate mere errors of reading. 



From the whole of these observations I think we may conclude that 

 Arcturus gives to us considerably more heat than a Lyrse ; that the amount 

 of heat received is diminished very rapidly as the amount of moisture in the 

 air increases ; that nearly the whole heat is intercepted by the slightest 

 cloud ; that as first approximations, the heat from Arcturus, at an altitude 

 of 25°, at Greenwich is about equal to that from a three-inch cube contain- 

 ing boiliug water at a distance of 400 yards. 



The heat from a Lyrse at an altitude of 60° is about equal to that from 

 the same cube at a distance of about 600 yards. The form given to the pile 

 appears likely to be useful in many inquiries respecting differences of heating- 

 power. 



January 20, 1870. 



Dr. WILLIAM ALLEX MILLER, Treasurer and Vice-President, 



in the Chair. 



The Presents received were laid on the Table, and thanks ordered for 

 them, as follows : — 



Transactions. 



Christiania: — Kongelige Xorske Frederiks Universitet. Aarsberetning 

 for Aaret 1868. Svo. Christiania 1869. Index Scholarum, 1S69. 

 4to. Christiania 1SG9. Forhandlinger i Yidenskabs-Selskabet i 

 Christiania, Aar 186S. Svo. Christiania 1869. Forhandlinger ved 

 de Skandinaviske Xaturforskeres, tiende Mode i Christiania fra 

 den 4 de til den 10 de Juli 1S68. Svo. Christiania 1869. Xyt Ma- 

 gazin for Xaturvidenskaberne. Bind I. Heft 1, 1835 (1S69) ; 

 Bind XYI. 8vo. Christiania 1869. Anton Rosing, Biographie, par 

 P. Chr. Asbjornsen. Svo. Christiania 1869. La Xorvege Litte'- 

 raire, par P. Botten-Hansen. Svo. Christiania 1868. Traite Ele'- 

 mentaire des Fonctions Elliptiques, par O. J. Broch. Svo. Chris- 

 tiania 1867. Qucllen zur Geschichte der Taufsymbols und der 

 Glaubensregel von C. P. Caspari. II. Svo. Cliristiania 1869. Micro- 

 metric Examination of Stellar Cluster in Perseus, by O. A. L. Phil. 

 4to. Christiania 1869. Skolevoesenets Ordning i Massachusetts, af 

 H. Rissen. Svo. Christiania 1868. Le Glacier de Boiuni en Juillet 



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