DR. BALFOUR STEWART. 361 



there are inequalities having reference to planetary configurations. 

 He also shows that there is a great likeness between meteorological 

 and raagnetical phenomena, and suggests that a further study of sun- 

 spots may ultimately enable us to predict longer and longer meteoro- 

 loijical occurrences. 



Papers on the Heating of a DisTc hy Rapid Rotation in Vacuo. 1. 

 On the Heating of a Disk by Rotation in Vacuo in conjunction with 

 Prof. Tait (Proceedings of Royal Society, London, 1865). 2. On the 

 same subject in conjunction with Prof. Tait (Proceedings of Royal 

 Society, London, 1866). 3. On the same subject in conjunction Avith 

 Prof. Tait (Proceedings of Royal Society, London, 1873). 4. (A Pos- 

 sible Explanation of its Effect ?) On the Temperature Equilibrium of 

 an Liclosure containing a Body in Visible Motion (Literary and Phil- 

 osophical Society, Manchester, November, 1870). Dr. Stewart en- 

 deavors to explain the heating of a disk of rotation i7i vacuo by an 

 extension of the theory of exchanges. 



Papers on Solar Physics hy 3Iessrs. Warren De la Rue, JB. Stew- 

 art, and B. Loeviy (Preliminary Researches printed for private cir- 

 culation by Mr. De la Rue). First Series: On the Nature of Sun-spots 

 (1865). Second Series: Area Measurements of Carrington Observatory, 

 and Deductions therefrom (1866). Third Series: On the Distribution 

 of Spots in Heliographic Latitude. 



Keio Researches. 1. Heliographic Positions and Areas of Sun- 

 spots observed with the Photoheliograph during the Years 1862 and 

 1863 (Transactions of Royal Society, London, 1869). 2. Positions and 

 Areas of Sun-spots observed at Kew during the Three Years 1864 

 -'66, as well as Fortnightly Values of Spotted Solar Area from 1832 to 

 1868 (Transactions of Royal Society, London, 1870). 3. On Some Re- 

 cent Researches in Solar Physics, and a Law regulating the Time of 

 Duration of the Sun-spot Period (Proceedings of Royal Society, Lon- 

 don, 1871). 4. Further Investigations on Planetary Influence upon 

 Solar Activity (Proceedings of Royal Society, London, 1872). 5. On 

 a Tendency observed in Sun-spots to change alternately from the one 

 Solar Hemisphere to the other (Proceedings of Royal Society, Lon- 

 don, 1873). 



Besides various miscellaneous papers, not mentioned here. Dr. 

 Stewart is the author of the following woi-ks : 



An Elementary Treatise on Heat ; Lessons in Elementary Physics ; 

 Conservation of Energy ("International Scientific Series"); and The 

 Unseen Universe (in conjunction with Prof. Tait). 



