372 
a course in science or agriculture at a university or 
college of agriculture, and should have had special 
training in the science and practice of dairying. Forms 
of application and copies of the regulations governing 
the appointment may be had from the Secretary of 
the Ministry, 10 Whitehall Place, S.W.1. Applica- 
tion forms must be returned by March 26. 
WE have received intimation of the opening at Lake 
Trasimeno of a laboratory for the study of the biology 
of the lake, including researches on the fresh-water 
fishes. The lake, which is about thirty miles in 
circumference, offers many opportunities for limno- 
logical work. It is to be hoped that this new station 
will receive the support which will justify its con- 
tinuance. The premises have been provided by the 
University of Perugia, and Dr. Osvaldo Polimanti, 
professor of physiology in the University, has been 
appointed director, and intending workers should 
communicate with him. 
Mr. G. M. B. Doxsson will deliver a lecture to the 
Royal Meteorological Society on March 21 on “ The 
Characteristics of the Atmosphere up to 200 km., as 
obtained from Observations of Meteors.’’ Meteoro- 
logical observations in the free atmosphere by 
means of ballons-sondes have not been carried to 
NATURE 

#8 
[Marcu 17, 1923 
heights much greater than 30 kilometres, but Prof. 
Lindemann and Mr. Dobson have recently put 
forward a method of determining the temperature 
at much greater elevations by means of observations 
of meteors (see NATURE, December 9, 1922, p. 794). 
Those interested are invited to attend the meeting, 
which will be held in the Society’s rooms at 49 Crom- 
well Road, South Kensington, London, S.W.7. 
At the annual general meeting of the Institute of 
Metals held on Wednesday, March 7, the following 
officers for the year 1923-24 were elected :—President: _ 
Mr. Leonard Sumner. Past-Presidents : Sir Gerard A. 
Muntz, Bart., Engineer Vice-Admiral Sir Henry J. 
Oram, Sir George Beilby, Prof. H. C. H. Carpenter, 
and Engineer Vice-Admiral Sir George Goodwin. 
Vice-Presidents : Sir John Dewrance, Mr. W. Murray 
Morrison, Sir Thomas Rose, Dr. W. Rosenhain, Sir 
William E. Smith, and Prof. T. Turner. Honorary 
Treasurer: Mr. A. E. Seaton. Members of Council : 
Mr. W. H. Allen, Mr. L. Archbutt, Mr. G. A. Boed- 
dicker, Mr. T. Bolton, Dr. H. W. Brownsdon, En- 
gineer Vice-Admiral R. B. Dixon, Prof. C. A. Edwards, 
Mr. S. Evered, Dr. R. S. Hutton, Mr. F. C. A. H. 
Lantsberry, Sir Charles A. Parsons, Mr. H. A. Ruck- 
Keene, Dr. R. Seligman, Mr. James Steven, Mr. F. 
Tomlinson, and Mr. H. B. Weeks. 

Our Astronomical Column, 
GREAT FIREBALL IN NORTHERN INDIA ON I)ECEMBER 
28, 1922.—Mr. W. F. Denning writes that “ letters 
have been received reporting a splendid fireball which 
appeared over the Punjab at about the time of sunset 
on December 28. It was observed by a great number 
of people, and accounts published in the Civil and 
Military Gazette (Lahore) include descriptions from 
Simla, Peshawar, Balloki, Moghalpura, Sargodha, 
Jhelum, Rawalpindi, Bakloh, Dharamsala, Lahore, 
Sharaqpur, Murpur, and other stations. 
Many of the accounts are of little service, but 
Col. W. E. Pye and Lieut. Stephenson at Shagai, 
Khyber Pass, North-West Frontier, give an excellent 
description of the phenomenon. The observed path 
at the latter place was from 6°-43° to 20°-48°, and the 
fireball exhibited moderately slow motion. It left 
a long white streak which endured about fifteen 
minutes, A large number of the observers allude to 
the streak as perfectly straight at first, but it soon 
assumed a zig-zag shape, and drifted away from the 
place of its early projection. At one station the 
streak, which appeared to be vertical when formed, 
became horizontal in twelve minutes, the lower end 
having moved the required distance. At Sargodha, 
six minutes after the great illumination due to the 
meteor, loud rumbling sounds were heard, caused by 
the disruption of the object. These would indicate 
a distance of 75 miles. 
From a comparison of the observations the fireball 
seems to have been an early Quadrantid with a 
radiant at 234°+55°. The height was about 54 to 
29 miles, and velocity about 25 miles per second. 
The luminous course was directed from N.N.W. 
to S.S.E. It crossed the river Chenab, and ended 
about 100 miles N.E. of Mooltan. 
These results are only approximate. The object 
was one of great splendour, and it is hoped that 
further observations will be forthcoming. 
NO. 2785, VOL. 111] 

STELLAR SPECTRA OF Crass S.—In the current 
number of the Astrophysical Journal (December 1922) 
Mr. Paul W. Merrill directs attention to a number 
of red stars having spectra similar to that of R 
Geminorum, which differ from any of the well-known 
types of spectra which form the Harvard classifica- 
tion. In this classification the red stars are known 
as M and N types and each of these is subdivided, 
but no stars are known which have a spectra inter- 
mediate between them; M stars have characteristic 
titanium flutings and N stars carbon flutings. i 
peculiarity has led to the adoption of a break in the 
main series of stellar evolution types of spectra. 
Thus an M star of increasing temperature becomes 
consecutively in the evolutionary series a K, G, F, 
etc., type star, while an N star, also a giant, becomes 
an Ro, G, F, etc., type star in its progressive stages. 
Mr. Merrill shows in this paper that the stars he has 
discussed should properly form a third division of 
the giant series joining on to the main sequence of 
evolutionary stages between the types Ma and K. 
This progression may be likened to three sets of rail- 
way lines joining up at two positions near each other 
and continuing as a single line. Thus: ‘ 
a Ro - Na Nba 
BAFGK Ma Mb Me 
< K 
eS Se 
It is interesting to note that the Harvard classifica- 
tion is based to a great extent on the replacement of 
metallic lines by ionised lines, and eventually by 
gaseous lines, the higher the temperature; but Mr. 
Merrill points out that while some M stars show 
ionised lines, so also do the S stars; this presents, as 
he says, ‘‘an anomalous circumstance which invites 
investigation.” 
