74 



SCIENCE. 



[N. S. Vol. XVI. No. 393_ 



per crocetta).* That method, which is of un- 

 known antiquity, is open to two very grave 

 objections. The first is that the result is ob- 

 tained from the right. The second is that 

 the attention must be continued from the first 

 to last. As a consequence of this last objec- 

 tion no one but a very clever computer can 

 use the method with any success.f 



D. N. Lehmee. 

 University of California. 



CURRENT NOTES ON METEOROLOGY. 



ECLIPSE METEOROLOGY. 



That interesting subdivision of meteorol- 

 ogy which is concerned with the meteorolog- 

 ical phenomena of solar eclipses is developing 

 rapidly. Professor F. H. Bigelow, of the 

 Weather Bureau, devotes the whole of 'Bul- 

 letin,' a quarto of 106 pages, to ' Eclipse 

 Meteorology and Allied Problems.' In this 

 memoir he gives the results of a critical 

 study of the direct meteorological phe- 

 nomena of the solar eclipse of May 28, 

 1900, as well as a discussion of cer- 

 tain relations between solar and terrestrial 

 meteorology in connection with the magnetic 

 and electric fields in the atmospheres of sun 

 and earth. Professor Bigelow has devoted 

 himself very largely for several years past to 

 this latter subject, and his work along these 

 lines has already become well known to those 

 who have a special interest in them. Pro- 

 fessor Bigelow has persistently maintained 

 that investigation of solar magnetic and al- 



* Cantor, ' Geschiehte der mathematik,' Band 2, 

 p. 286. Also 'Das Reehnen in 16. Jahrhundert,' 

 von P. Treutlein, Zeitschrift fiir Math, unci 

 Physik, Suppl. zu XXII., 1877, p. 49. 



f Since writing the above my attention has 

 been called by Professor D. E. Smith to a method 

 described by El-Hassar about the 12th century, 

 which has some points in common with mine. 

 For an account of his work see an article- by 

 Suter, ' Das Rechenbuch des Abu Zakarlja El- 

 Hassar ' in Bihliotheea Matjiematica, 11, p. 16 

 (1901). El-Hassar obtains his product from the 

 left, but adds each cross product as he obtains it, 

 thus making the work complicated and confu- 



lied problems is an essential to the further- 

 advance of scientific meteorology, and he has 

 labored steadily and enthusiastically towards 

 the solution of some of these complex prob- 

 lems. 



The portion of the 'Bulletin' which is more 

 immediately related to the purpose of these- 

 Notes concerns the meteorological work done 

 by the eclipse expedition to Newberry, S. C.;. 

 the special meteorological observations at 

 sixty-two Weather Bureau stations, and a con- 

 siderable number of voluntary special obser- 

 vations. On the basis of these data Professor 

 Bigelow has made studies of the variations 

 in pressure, temperature, vapor tension and 

 wind caused by the passage of the shadow; 

 of the shadow band phenomena, which ap~ 

 pear to be due to meteorological conditions- 

 exclusively; and has also computed the num- 

 ber of calories of heat per kilogram absorbed 

 at the earth's surface by the shadow. As to 

 the variations in piressure, it appears that the- 

 mean curve, based on pressure readings made- 

 at a number of stations, is so smooth that it 

 cannot be positively asserted that the eclipse 

 caused a rise shortly before totality, or a. 

 drop later. The temperature curves sho-w 

 clearly defined variations, the greatest lower- 

 ing of the temperature being about 3.5° in 

 the total shadow. The vapor pressure curves 

 are very irregular, but the means show that 

 there was a decrease of vapor tension of about 

 0.01 inch at the time of the maximum cooling 

 of the air. There was a decrease in the wind 

 velocity of about one mile per hour caused by 

 the eclipse shadow, but Professor Bigelo-w's 

 results as to wind direction seem to him to in- 

 dicate ' that tliere was no definite change in the- 

 azimuth which could be attributed to the 

 eclipse.' The facts seem to Professor Bige- 

 low to 'exclude the possibility that any sort 

 of a true cyclonic circulation was generated 

 by the action of the cooling effect of the 

 moon's shadow on the atmosphere.' In this,. 

 Professor Bigelow is not in agreement withi 

 Mr. H. H. Clayton's results (Annals Harv. 

 Coll. Ohsy., XLIII , Part I., 1901, 1-3.3. See 

 also ScTEXCE, April 13, 1901, 589-591; May- 

 10, 1901, 747-750), to a discussion of which 

 some attention is given. Professor Bigelow 



