4 ART. 10'.— K. HONDA & S. SHIMIZU. 



diminished on one side by another partition placed 5 cm above the 

 lower end of the coil, and on the other side, by a bundle of fibrous 

 asbestos attached to the copper rod just below the same end. 



The exposed parts of the copper rods and wire were well covered 

 with asbestos paper, except the part where the wire came in contact 

 with the rotating cylinder. This precaution was necessary to 

 diminish the loss of heat, and also to avoid the oscillating displace- 

 ment of the image in the field of the telescope due to thermal ex- 

 pansion and contraction caused by the air current. 



The temperature of the samples to be tested was measured by 

 means of a platinum rhodium-platinum junction which Avas loosely 

 placed in contact with the sample at its middle part, while the rest 

 was insulated with asbestos paper. The other junction, also well in- 

 sulated, was inserted into a copper tube dipped in a water bath of the 

 temperature of the room. The thermoelectric current in the circuit 

 was measured by a d'Arsonval galvanometer, and the constant of the 

 pyrometer was determined by means of a mercury thermometer below 

 300°C, and by the melting points of zinc and sodium chloride above 

 that temperature. 



A magnetizing coil with a water-jacketed arrangement was placed 

 co-axially with the suspended rod ; it was 40 cm long and gave a 

 field of 39.4-4 C.G.S. units at the center due to a current of one 

 ampere. 



When the adjustment was finished, the exposed parts were well 

 covered with fibrous asbestos and cotton in order to diminish the loss 

 of heat, care being taken to produce no sensible resistance to the 

 elongation or contraction -of our specimens. 



For the measurement of the magnetic change of length in liquid 

 air, the above arrangement was modified in the following way. The 

 specimen was stretched upwards by means of a spiral spring, 



