Febeuaey 14, 1902.] 



SCIENCE. 



261 



tions at a number of stations distributed 

 along the belt of totality, as was done last 

 year, and thus testing whether the magnetic 

 effect again followed directly in the wake of 

 the shadow cone, were not favorable owing 

 to thepresent location of the belt of totality. 

 In response to the appeal, simultaneous 

 magnetic observations were made on May 

 17 from 14 to 21 o'clock, Greenwich mean 

 astronomical time— an interval amply cov- 

 ering the time of the eclipse— at a number 

 of stations encircling the entire globe, three 

 of which were in the belt of totality. The 

 prime purpose of making the observations 

 so as to cover the entire globe was to fur- 

 nish the possibility of separating a possible 

 eclipse magnetic effect from a contempo- 

 raneous magnetic storm of the usual type. 

 The eclipse effect, for instance, doubtless 

 would be confined to a very small belt, 

 whereas a customary magnetic storm, in 

 eonfonnity with the usual experience, 

 would manifest itself at practically the 

 same moment of time over a very large 

 area, and thus be felt at stations far from 

 the totality belt. At none of the outside 

 stations has a disturbance of any appreci- 

 able size been thus far reported to me, the 

 general consensus of opinion of observers 

 at these stations being that ' nothing un- 

 usual occurred.' At the three 'stations 

 within the belt of totality the majority of 

 the opinions is that something unusual did 

 occur during the time of the eclipse. Thus 

 at Karang Sago, where was situated the 

 Dutch eclipse party, Dr. W. van Bermelen, 

 assistant director of the Batavia Magnetic 

 Observatory, observed the change in the 

 magnetic declination and horizontal in- 

 tensity, and he reports the occurrence of an 

 extremely interesting mag'netie effect.' He 

 has courteously sent me an extract of his ob- 

 servations made during several days before 

 and on the day of the eclipse, and there cer- 

 tainly appears evidence of a magnetic 

 effect in both elements different from that 



observed on the days prior to the eclipse. 

 At Sawah Loento, the site of the Massa- 

 chusetts Institute of Technology party, of 

 Boston, the variations in magnetic declina- 

 tion were observed by Mr. G. L. Hosmer on 

 May 17 and 18. Comparing the two days' 

 results for the interval of the eclipse, there 

 is indisputable proof that something differ- 

 ent occurred on the day of the eclipse than 

 on the day before. Namely, at this station, 

 situated so close to the magnetic equator 

 the range of the diurnal variation of the 

 magnetic declination is about one minute of 

 are. The magnetic effect during the time 

 of the eclipse was of about the same amount, 

 so that a steady decrease of east declination 

 resulted during the time of day when nor- 

 mally there is a steady increase. There 

 was but one magnetic observatory directly 

 ■within the belt, viz., the one at Mauritius 

 and this was situated not far from the 

 place of beginning of the eclipse. No spe- 

 cial magnetic observations were made at 

 this place; however, the regidar photo- 

 graphic ciirves giving the variations in the 

 magnetic elements were obtained. The dec- 

 lination and the vertical intensity curves 

 apparently do not show any disturbance 

 that could easily be picked out and referred 

 to the eclipse. Regarding the horizontal 

 intensity curve— the more sensitive one — 

 Mr. Claxton states ' that the original curve 

 shows slight tremors between 7.15 and 7.50 

 and occasionally between 8.5 and 9.0 a. m.' 

 I have plotted this intensity curve on a 

 large scale and find that the curve shows 

 no very marked disturbance that might be 

 readily referred to the eclipse, with the ex- 

 ception of one producing an easily per- 

 ceptible bulge in the curve amounting to 

 about 3-4 units in the fifth decimal c.g.s. 

 units and lasting about 30 minutes. Any- 

 way the effect, if there be one, is very 

 minute, and will not be so readily separated 

 from the usual diurnal variation as in the 

 case of the two previous stations. "Whether 



