March 24, 1892 J 



NA TURE 



49; 



storm; but, except when the advent of a vortex can be 

 distinctly traced to the highlands of the western frontier, 

 it seems very likely that its development and duration are 

 in some degree influenced by the local conditions of the 

 land surface, such as have been already noticed in the 

 case of the Northern Punjab ; and its intensity would 

 seem to be mainly dependent on the amount of snow and 

 rain that is precipitated. 



From what has been said above, the general resem- 

 blance of the winter storms of Northern India to those 

 of our own latitudes will be sufficiently obvious. In their 

 eastward movements, the localization of the rainfall, 

 the contrasted temperature conditions of the opposite 

 quadrants, and many other particulars, we may recognize 

 their essential identity. But certain features which are 

 more or less blurred in our European storms, in those that 

 we are now dealing with stand out with much clearer 

 definition ; and they seem calculated to throw not a little 

 light on the still vexed question of storm generation, and 

 perhaps to reconcile some of the very conflicting views 

 that now prevail on this subject. As Mr. Lewis Morris 

 says of the old Greek myths — 



" These fair tales which we know so beautiful 

 Show only finer than our lives to-day 

 Because their voice was clearer and they found 

 A sacred hard to sing them" — 



so may we say of these manifestations of aiirial action in 

 India. The phenomena are similar in kind to those 

 that pass before our own eyes, but they stand out, 

 accentuated by the circumstances of the climate and 

 country, with a clearness and prerogative emphasis that 

 we may seek for in vain in the confused and kaleido- 

 scopic weather phases of these latitudes. We read 

 their meaning almost at a glance, as we gather that 

 of a printed page, and have not laboriously to pick 

 out and piece together the obscure facts that express it, 

 as with painful effort we might decipher the faded and 

 half-concealed characters of a monkish palimpsest. And by 

 good fortune, we have at the head of the Indian Meteoro- 

 logical Department an accomplished mathematician and 

 physicist, who appreciates to the full the rich opportuni- 

 ties of his charge, and who knows how to marshal and 

 interpret his facts as well as record them. 



Henry F. Blanford. 



THE MAGNETIC STORM OF FEBRUARY 

 13-14, 1893. 



THE Superintendent of the U.S. Naval Observatory 

 sends us the following records of the magnetic storm 

 of February 13 : — 



" The records of this unusually severe magnetic 

 storm are of especial interest as occurring at the same 

 time as the fine displays of aurorao and the appearance of 

 a large group of sun-spots. 



"The first increase in the horizontal force was followed 

 by a rapid decrease, the force falling to much less than 

 its usual strength, with rapid changes. Its change during 

 the storm was 24 per cent, of its mean strength. The 

 vertical force decreased so much that the sensitive 

 balanced magnet used to record it was upset at 8 p.m. of 

 the 13th, and its further record lost. 



" The auroras were seen at Washington at about 2 a.m. 

 and 7.30 p.m. of the 13th, the latter time being marked by 

 an unusually disturbed condition of the magnets." 



o 



DECLINATION l^^r^'" ^ U 



..,,. ____ _ 1° EAST I 



:,,,VERTIC^FORCE 



K 





HORIZONT/VL''\FORCE 



'/IDNIGHT ! ■ i I "••'''' I 



1 — i — \ — r 



WEST 



L. io' 



\ P(A NOON 

 ■■^ \^ FEB 13 



•' The magnetic storm commenced suddenly at 1 2.40 a.m. 



5th meridian time), February 13, with a movement of 

 uie north end of the declination magnet to the westward, 

 and a rapid increase in the horizontal and decrease in the 

 vertical components of the earth's magnetic force. 



" The north end of the declination magnet remained to 

 the westward of its normal position until 10.30 a.m., when 

 it crossed to the eastward, all the time oscillating violently, 

 and did not return to the normal until 8 p.m. of the 13th, 

 after which it kept oscillating on each side of its mean 

 position until the end of the storm. It registered a change 

 <ii direction of ih\ 



NO. I 169, VOL. 45] 



WILLIAM DITTMAR. 



A LL who take an interest in the progress of chemistry 

 -^^ will regret the death of William Dittmar ; a smaller 

 circle feel that they have lost an invaluable friend. Born 

 at Umstadt, near Darmstadt, April 15, 1833, he was the 

 second son of Fritz Dittmar, then Assessor at Umstadt, 

 afterwards Landrichter at Ulrichstein, in Ober-Hessen, 

 where he took a part in the movements of 1848 dis- 

 pleasing to the Hessian Government, who removed him 

 from office, allowing him to retire on a pension. At the 

 age of sixteen, therefore, William became a resident in 



