June 2, 192 1] 



NATURE 



427 



Its mean heliographic co-ordinates on that date were 

 latitude +14°, longitude 6-4°. The following spot was 

 a large single spot, and its co-ordinates were latitude 

 02°, longitude 3588°. The whole group extended over 

 12° in longitude and about 6° in latitude, so that a con- 

 siderable area of the sun's surface was disturbed. 



The mean heliographic latitude of the earth during 

 the passage of the group across the sun was —2-8°. 

 Therefore, not only was there a large active sun-spot 

 on the sun, and with the penumbral character which 

 frequently marks spots associated with magnetic dis- 

 turbance, but also the earth was very favourably 

 situated with regard to it. Under such conditions a 

 great magnetic storm is inevitable. 



With regard to the registration of the movements 

 of the needles during the series of magnetic disturb- 

 ances, we were greatly handicapped by the non-arrival 

 of our usual supplies of sensitive photographic paper. 

 Even so, on the less sensitive paper we were obliged 

 to use the records were very remarkable. As early as 

 May II the D (declination) magnet was affected by 

 some small rapid oscillations from 6h. 12m. to 8h. 12m. 

 The next day, May 12, between 8h. and loh., D was 

 still more disturbed, while at 8h. 12m. H (horizontal 

 force) showed a marked and rapid fall of 1467. 



A greater activfty of disturbance began on May 13 

 with a "sudden commencement" at i3h. 12m. In 

 D there was a rapid movement to east and west of 

 extreme range 15°, and on V (vertical force) an 

 increase, decrease, and rapid recoven% range 267, in 

 about two minutes. This phase is somewhat unusual 

 on V. Between 2ih. 24m. and 2ih. 36m. a rapid 

 oscillation of D occurred, east, west, and east, range 

 28'. At the same time V fell rapidly and suddenly 

 -^i^y, recovered for a few moments with a slight rise 

 at 2ih. 36m., and then fell so that the spot of light 

 was off the recording drum. At 22h. 12m. It rose 

 again rapidly 2507. Just before midnight there were 

 further active movements of D and of V. 



The second and more intense phase of the storm 

 commenced on May 14 i6h. On D a series of oscilla- 

 tions occurred of increasing speed and amplitude until 

 22h. 22m., when there was a sharp eastward move- 

 ment of 46'. At the same minute there commenced a 

 verv rapid decrease of force in V of at least 4617, 

 the spot of light passing oflf the paper on May 15 

 oh. 24m., the magnet adhering to the arrests. It did 

 not begin to give a record again until May 15 

 gh. 12m., when it had risen to its position before the 

 rapid fall. 



Meanwhile D was becoming more violently agitated 

 until on May 15 oh. 45m. the spot of light passed 

 off the drum in an eastward direction. This marked 

 the commencement of the third, or most intense, 

 phase of the storm, which lasted for about eight 

 hours. The movements of D were so rapid that the 

 paper used was not sensitive enough to register all 

 their details. At 5h. 24m. the spot of light had 

 reached the limits of record in the westward direc- 

 tion, so that the extreme range of D during the storm 

 was greater than 2° 9'. It was not until yh. 30m. 

 that the movements had decreased in intensity suffi- 

 ciently to be clearly legible on the curves. The spot 

 of light was then east, and it rose west with a series 

 of rapid oscillatory movements between 8h. and iih., 

 when it attained a normal position. The mean range 

 of these oscillations was 20'. 



With regard to H, the trace after May 14 22h. 2.i;m. 

 and during the maximum phase is completely lost 

 owing to the inferior sensitiveness of the paper. The 

 record is resumed on May 15 yh. 30m. This agrees 

 with D in giving the greater and greatest intensities 

 of the storm as occurring between May 14 22h. 25m. 

 and May 15 ih. 30m. 



NO. 2692, VOL. 107] 



On May 16 D continued to be disturbed, particularly 

 between oh. and iih., with a range of 47', the more 

 rapid oscillations taking place between 4h. and loh. 

 This is a repetition as to time of the storm of the 

 preceding day, though on a reduced scale. On H 

 the activity was even greater than on D, the range 

 being 3297. On V the spot of light fell gradually, 

 until on May 16 6h. .50m. it had passed off the 

 paper. It came on again after about 12 minutes, 

 and the magnet gradually resumed a normal position. 

 The range was 4107. The character of its trace was 

 a long wave with superposed oscillations. During 

 the storm the variations in V were extremely and 

 unusually active. 



Magnetically, May 17 was comparatively, though 

 not actually, a quiet day, and May 18 was even 

 quieter. Greater activity was resumed on May 19 

 2oh., when the sun-spot, much reduced in disc-area, 

 was approaching the western limb of the sun. Be- 

 tween 23h. and 23h. 46m. there was a well-marked 

 peak-like movement on D, with a range of 58'. H 

 was not so much disturbed as D. But on May 20 

 23h. 5m. to May 21 oh. 5m. there was a move- 

 ment on H of a similar peaked character to that of 

 D on the preceding day. The range was 2127. V, 

 too, was again active, range 1737, between May 19 

 2ih. and May 20 3h. 30m. On May 20 I4h. 30m. 

 there was resumed activity on the magnets, with rapid 

 oscillations on D and H and an increase of force in 

 both H and V. The series of disturbances, con- 

 stituting a storm of unusual duration, had not com- 

 pletely subsided until May 21 2oh. A. L. Cortie. 



Stonyhurst College Observatory, May 27. 



The Reparation Act and Scientific Research. 



Prof. Partington's letter (Nature, May 26, p. 394) 

 interested me, because some months ago I pointed out 

 in Nature how harmful any restriction of the im- 

 portation of scientific apparatus would be to some 

 scientific laboratories, and how unreasonable the 

 claims of the English instrument-makers appeared to 

 me. However, no one else wrote in support of what 

 I said and several makers wrote against it (though 

 carefully refraining from answering my criticisms), 

 and I almost began to think that my experience might 

 be unusually unfortunate and that other workers were 

 not affected, especially as Nature in certain leading 

 articles supported the protection of "key industries." 

 The Gilbertian "Reparation " Act is of later date, but 

 instances of its working are supplied in the letters of 

 Prof. Gardiner and Prof. Partington. 



Now there is not the slightest hope that the weak 

 influence of scientific workers will affect the plans of 

 practical politicians and Civil Service officials, 

 especially after the recent action of the Post Office 

 when opposed by much more powerful interests. 

 Nevertheless, I am surprised that none of the scientific 

 societies has taken the action of ascertaining the feel- 

 ing of its members on this question. They could then 

 either repudiate the statements of the grumblers, of 

 whom Prof. Partington may be reckoned one, or pub- 

 lish some manifesto which could be placed on record 

 as a protest against the policy of protecting scientific 

 apparatus at the expense of science. 



It is reported that the president of the Society of 

 Glass Technology, speaking on the restriction of im- 

 portation of glassware, considered that "electric lamp 

 bulbs should also have been included in the Bill," and 

 I agree, as that might have attracted more public 

 attention to the effects of the Bill. 



J. S. DUNKERLY. 



Zoological Laboratory, The University, 

 Glasgow. 



