IV. MAGNETISATION. 285 



in two directions, perpendicular to one another. The other apparatus is a 

 needle, called "unipolar," suspended by means of a cocoon thread, with two 

 microscopes. 



1127. Ring of Elias for magnetising artificial magnets of large 

 size. Teyler Foundation, Haarlem. 



A magnet of 28 kilogrammes weight has been recently magnetised by this 

 ring in Teyler's Museum. 



Dr. Elias proposed more than 25 years ago his ring-coil for the production 

 of artificial magnets of all dimensions, by an intense galvanic current. His 

 artificial magnet here exhibited has lately been re-magnetised, with a slight 

 modification of his method by Prof. Van der Willigen in the Teyler Museum, 

 by this ring with the current of forty Bunsen elements of the usual large 

 size. 



1128. Apparatus for showing to an audience the effects of 

 the superficial tension of liquids (Tomlinson's Cohesion Figures) ; 

 magnetic curves or the movement of liquid films, &c. 



Prof. W. F. Barrett. 



1129. Bar of Metallic Nickel, 20 inches long and inch 

 diameter. George Gore, F.fi.S. 



1130. Three Plates of Metallic Nickel, 6 inches long and 

 1J inch wide. George Gore, F.R.S. 



1131. Small Nickel Horseshoe, for making a Nickel 

 Magnet. George Gore, F.fi.S. 



1132. Plate of Metallic Cobalt, 6 inches long and 1^ inch 

 wide. George Gore, F.R.S. 



1135. Horseshoe Magnet of Nickel, used by Sir William 

 Thomson in his experiment on the effect of magnetism on the 

 thermo-electric quality of nickel. Result published in the Trans- 

 actions of the Royal Society for the year 1856, Bakerian Lecture. 



Edinburgh Museum of Science and Art. 



1136. Apparatus for showing a series of molecular and mag- 

 netic changes in a red-hot iron bar ; and designed also to show 

 the influence of traction, compression, and torsion upon such 

 changes. The latter experiments have not yet been made with it. 



George Gore, F.R.S. 

 See Philosophical Magazine, Sept. 1870. 



1136a. Apparatus for exhibiting molecular changes occur- 

 ring during the heating and cooling of iron wire. 



Prof. W. F. Barrett. 



When an iron or better a steel wire is raised to a white heat, a sudden 

 contraction occurs at a dull red heat, the apparatus exhibits the phenomenon 

 first noticed by Mr. Gore ; when the wire is allowed to cool after being 



