﻿Photographing, and exhibiting the Magnetic Spectra. 479 

 Magnetic Lines of Force (from a photograph by the Author)*. 



[* For the loan of this woodcut we are indebted to Messrs. Longmans, 

 the publishers of Professor Tyndall's recent volume, 'Fragments of Science/ 

 of which it forms one of the illustrations. — W. F.] 



