Cavendish Magnetic Laboratory Report for the Year 1929-30 States ' The main line of research has been directed to the study of magnetic susceptibility and magnetostricition in different substances in strong magnetic fields. A special balance has been constructed by means of which the magnetisation could be measured in magnetic fields existing for 1/100 of a second and reaching the value of 300,000 gauss. A number of substances have been investigated at ordinary temperatures and the Langevin Law of magnetisation was verified over a range of magnetic fields up to 300,000 gauss at ordinary temperatures; the work is now going to be extended to lower temperatues. ' Refers to work by Dr Webster who ' studied magnetic and calorific phenomena during the process of growing bismuth crystals with a view to finding out the conditions governing he growth of the perfect crystal 'and Dr Sinelnikoff who has ' worked on the change of resistance of single crystals of cadmium, tin and zinc, and has verified certain theoretical laws which were estqblished in this laboratory for strong magnetic fields.' ' Designs for a liquid helium plant had already been started.' 1929 - 1930