SECTIONAL TRANSACTIONS— A. 389 



The experiments were chiefly concerned with the study of the * ferro- 

 magnetic ' properties of iron-ammonium alum at very low temperatures, 

 which were also extended to diluted salts and to an investigation in addi- 

 tional fields. The reasons which may be responsible for this ' ferro- 

 magnetism ' are discussed. A new method for establishing temperatures 

 on the absolute scale is described. 



Discussion continued in afternoon (see below). 



Sir J. J. Thomson, O.M., F.R.S. — Some recent experiments on electronic 

 waves (12.15). 



(concurrently with above session.) 



Joint Discussion with Section G (Engineering) on Fundamental 

 magnetic measurements with special reference to incremental con- 

 ditions (lo.o). (See under Section G.) 



Afternoon. 

 Discussion on Low temperature physics (continued) (2.15). 



Dr. K. Mendelssohn. — Recent developments in superconductivity. 



Dr. E. T. S. Appleyard. — The superconductivity of thin mercury 

 films. 



Dr. H. Jones. — The superconductivity of alloys. 



Dr. N. Kurti. — Experiments belozv 1° absolute. 



Mr. E. S. Shire.— Paramagnetic relaxation below 1° absolute. 



Dr. H. B. G. Casimir. — Spin-lattice interaction. 



Mr. J. Ashmead. — The production of intense magnetic fields for magnetic 

 cooling experiments. 



Mr. J. G. Daunt. — New experiments on the transfer effect. 



Dr. H. London. — Investigation of liquid helium II by a Knudsen 

 manometer. 



Dr. E. Ganz. — The thermal conductivity of liquid helium II under 

 pressure. 



Mr. A. H. Cooke. — The attainment of low temperatures by pumping 

 off liquid helium. 



Mr. PiCKARD. — The construction of a standard expansion liquefier. 



Visit to works of British Tabulating Machine Co., Letchworth. 



