February 6, 19 13] 



NATURE 



629 



several observatories, of the magnitudes of Nova 

 Geminorum No. 2, are publislied in No. 4624 of the 

 Astronomische Nachrichten. In addition to the tables 

 giving the magnitudes recorded at the Berlin Ob- 

 servatory, Herr Freundlich publishes a light-curve 

 showing the v.ariations of the nova's magnitude from 

 March "14 to May 18, 1912. This curve agrees fairly 

 well with that previously published by Herr Fischer- 

 Petersen, and shows maxima, successively decreasing 

 in intensity, on March 14, 23, April 3, 19, and May i. 



Possible Changes of a Lunar Feature. — In the 

 Januarv number of L'Astronomie, M. Pierre Stoian 

 directs the attention of lunar observers to a small 

 "hill" which, according to his observations, under- 

 goes changes of form and size. This small feature lies 

 to the north of the line joining Thebit and Birt, and 

 about half-way between the former and the small 

 crater at the northern end of the Straight Wall. M. 

 Stoian points out that Nasmyth recorded nothing in 

 this position, Neison saw a double peak, and the 



being a wavy line, each minute being especially 

 marked ; the images of the transit-threads are also 

 impressed upon the plate, so that any plate may be 

 measured or re-measured at leisure, the time of start- 

 ing the exposure having been recorded. The excel- 

 lence of the images is shown by a plate, accompanying 

 the paper, and a comparison of Herr Triimpler's with 

 other results promises well for the photographic re- 

 cording of star transits. 



THE MARINE BIOLOGICAL STATION AT 

 PORT ERIN. 



THE twenty-si.xth annual report of the Liverpool 

 Marine Biology Committee gives evidence of the 

 rapidly increasing importance of the laboratory at Port 

 Erin as a centre for research and for the instruction of 

 students. The number of workers has more than 

 doubled during the last six years ; there were seventy- 

 four workers during the year 1912. The extension 



-The Port Erin Biological Station from the 



Paris photographs show a crescent-shaped eminence 

 which to Gaudibert was an oval ; others have recorded 

 it as larger than the smaller of the two small craters 

 in the N.E. wall of Thebit, while to some observers 

 it has appeared to be smaller. The feature appears 

 to be worth further attention on the part of seleno- 

 graphers. 



Photographic Transit Observations. — By the 

 munificence of Messrs. Krupp, Prof. Ambronn was 

 able to secure a photographic transit apparatus for 

 use at the Gottingen Observatory in the early part of 

 igii. The instrument has been tested and used by 

 Herr R. Triimpler, who describes it and the results 

 secured in No. 4620 of the Astronomische Nachrichten. 

 The focal length of the Gottingen instrument is 

 180 cm., the aperture 18 cm., and photographic 

 transits of stars down to the eighth magnitude may 

 b? secured. A slight relative displacement every 

 second results in the photographic trace of each star 



NO. 2258, VOL. 90] 



effected two years ago has been fully occupied, and 

 the director (Prof. Herdman) reports that already 

 further accommodation for research is urgently re- 

 quired. 



Among noteworthy matters mentioned in the report 

 are the weekly lessons and demonstrations given by 

 the curator (Mr. H. C. Chadwick) to the boys from 

 the local secondary school. 



Prof. B. Moore and his colleagues are carrying out 

 an extensive physiological and chemical investigation 

 into the nutrition and metabolism of marine organ- 

 isms. The results show that the amount of organic 

 carbon present in the sea-water is almost negligible, 

 being well below one milligramme per litre of water, 

 and that Piitter's estimates are incorrect. They also 

 show that, while the plankton-supply, as found gener- 

 ally distributed, may prove suflficient for the nutrition 

 of such sedentary animals as sponges and ascidians, 

 it is quite inadequate for active animals, such as crus- 

 taceans, molluscs, and fishes. These latter, however, 



