TRANSACTIONS OF THE SECTIONS. X] 



Department of Gknishal Physics. 



Page 



1. On the Radiation producing Aurora Borealis. By L. Veuard 322 



2. A Friction Penneametcr. By W. H. F. Murdoch, B.Sc, M.l.E.E 323 



3. On the Methods and Apparatus used in Petroleum Testing. By J. A. 



Harkee, D.Sc., F.R.S., and W. F. Higgins, B.Sc, A.R.C.S 324 



MONDAY, SEPTEMBER 4. 



Joint Discussion with Section G on Aeronautics. Opened by A. E. Berri- 



man (p. 481) 325 



Department of Mathematics. 



1. Proofs of certain Theorems relating to Adjoint Orders oi Coincidence. 



By Professor J. C. Fields 325 



2. A Theorem connected with Six Lines in Space. By H. Bateman, M. A. . . 32(3 



3. The Canonical Form of an Orthogonal Substitution. By Harold 



Hilton 320 



Department of General Physics. 



1. The Absolute Measurement of Current at the Bureau of Standards. By 



Dr. N. E. Dorsey 327 



2. On Peculiarities in the Adsorption of Salts by Silica. By Professor F. T. 



Trouton, Sc.D., F.R.S 328 



3. The Effects of Ah Currents on Sound. By Professor F. R. Watson .... 330 



4. The Vernier Arc : A New Form of Micrometer. By J. W. Gordon 330 



Department of Cosmical Physics. 



1. The Thunderstorms of July 28 and 29, 1911. By Dr. \V. X. Shaw. F.R.S. 331 



2. Report of the Seismological Committee (p. 30) 332 



3. Note on the Periodogram of Earthquake Frequency from Seven Years to 



Twenty Years. By Professor H. H. Turner, F.R.S 332 



4. Horizontal Pendulum Movements in relation to certain Phenomena. 



By F. Napier Denison, F.R. Met. Sec. . 335 



5. The Solar Cycle, and the Jamaica Rainfall and Earthquake Cycles. By 



Maxwell Hall, M.A., F.R.A.S 339 



(3. *Great Boundary Waves : Parallactic Tides set up in the Bottom Layers 



of the Sea by the Moon. By Professor 0. Pettersson 340 



