OBSERVATIONS 



OF 



MAGNETIC ELEMENTS 



BY 



E. YAMAGUCHI. 



I accompauieJ tlic expedition for the purpose of making magnetic 

 observations. The instrumental appliances were very imperfect and the results 

 necessarily rough. 



The determinations of the horizontal iuteusity were only relative, the 

 method beiug exactly similar to that adopted by Mr. Fujisawa in the expedi- 

 tion to Fujinoyaiiia and Sapporo. The method consisted in the determination 

 of the time of vibration of a horizontally suspended magnet. The mngnet 

 was suspiMided by a silk fibre about 30 cm. long, in a glass case on which 

 was pasted a scale for tneasuriog the arc of vibration. Silk fibres were also 

 fixed vei-ticaljy on the outside of the glass case near the middle of the scale. 

 The transits with reference to one of three fibres of a convenient point on the 

 end of the oscillating magnet could be easily observed, and when necessary 

 simultaneous records made on the chronograph, which was being used in the 

 gravity experiments. The adjustment of the magnet in the horizontal posi- 

 tion was done by suspending it close over a wooden surface already levelled. 

 The reading on the glass case did not give at once the true arc; but this 

 could be easily deduced as the diameter of the glass case and the length of 

 tlio magnet were known. 



Two magne tswere used. The one (named A) was cylindrical in form, 

 having a length of 17.3 cm. and a diameter of .8 cm. Its mass was Co. 8 

 gin. It was one of the two magnets kindly lent by the Kobu Daigakko and 

 used by Mr. Fujisawa at Sapporo. The other ouo had changed so much in 

 magnetic moment, that it was considered not worth using. Tiio second 

 magnet (named 15) was a rectangular block of square section, 11.2 cm. long 

 and 1.2 cm. square. Its mass was 139.3 gni. Each of tho magnets rested 

 iQ a brass or copper stirrup to which tho silk fibro was fastened. 



