TEANSACTIONS OF THE SECTIONS. 



Section A.— MATHEMATICAL AND PHYSICAL SCIENCE. 



THURSBA Y, A VG UST 26. 



Page 

 Address by Professor W. Gbtlls Adams, M.A., F.K.S., F.G.S., F.C.P.S., 



President of the Section 447 



1. Eeport of the Committee for the Measiu-ement of the Lunar Distui'bance 



of Gravity 458 



2. Eeport of the Committee upon the present state of our Knowledge of 

 Spectrum Analysis. (Influence of Temperatm-e and Pressure on the 

 Spectra of Gases) 458 



3. On deteradning the Heights and Distances of Clouds by then- reflexions in 

 a low pool of water, and in a mercurial hoiizon. By Fkancis Galtoit, 

 MA., F.R.S 459 



4. Improved Heliograph or Sim Signal. By Tempesi Audekson, M.D., 

 B.Sc 461 



5. Improved Apparatus for the Objective Estimation of Astigmatism. By 



Tempest Anderson, M.D., B.Sc 463 



6. On the Length of the Sun-spot Period. By Henry Mtttrhead, M.D. ... 465 



7. Siir la Calculation des Ph^nomenes periodiques. Par le Professeur 

 Ragona 466 



8. On the Laws of tlie Change of Speed and Direction of the Wind. By 

 Professor Ragona 467 



FRIDAY, AUGUST 27. 



1. Report of the Committee on Undergroimd Temperature 467 



2. Report of the Committee appointed to devise and construct an improved 

 form of High Insulation Key for Electrometer Work 467 



3. Comparison of Curves of the Declination Magnetographs at Kew, Stony- 

 hurst, Coimbra, Lisbon, Vienna, and St. Petersburg. By Professor W. 

 Grylls Adams, M.A., F.R.S 467 



4. On the best form of Magnet for Magneto-electric Machines. By W. Ladd, 

 PPA.S 467 



6. An Account of some Experiments in Photo-electricity. By G. M. Minchin, 

 M.A 468 



6. Electric Convection-Currents. By Silvantjs P. Thompson, D.Sc, B.A,, 



Professor of Experimental Physics in University College, Bristol^ 470 



7. On a peculiar behavioui- of Copper. By William Henbt Preeoe 470 



