January 14, 191 5] 



NATURE 



543 



suitable for a 500 brake-horse-power gas engine, and 

 \TOuld evaporate 1500 lb. of water an hour from and 

 at 100° C. from the heat in the exhaust gases alone. 

 Alternatively it would evaporate the same quantity when 

 fired with coal alone, and if worked simultaneously 

 by both methods, the evaporation would be about 

 3000 lb. an hour from and at 100° C. A large in- 

 crease in efficiency is claimed by application of the 

 system to open-hearth furnaces. 



The forty-second annual issue, that for 1915, of 

 '■ Willing's Press Guide and Advertisers' Director}- 

 and Handbook " has been received. This yearly book 

 of reference provides a concise and comprehensive 

 index to the Press of the United Kingdom, a list of 

 telegraphic news and reporting agencies, lists of the 

 principal Colonial and foreign journals, and a variety 

 of general information. A classified index of period- 

 icals will prove of special interest to librarians, who, 

 under such titles as "Chemical Science," '" Geolog}'," 

 "Astronomy," "Philosophy," will find lists of maga- 

 zines and journals devoted to different branches of 

 science. The price of this useful " guide " is \s. 



OUR ASTRONOMICAL COLUMN. 



Fireballs in January. — Though Januan,- is by no 

 means a month presenting special meteoric activity, 

 it has furnished quite an unusual number of large 

 fireballs. An analysis of the dates appears to show 

 that the following periods are rather strikingly indi- 

 cated : — 



Principal Radiants. 

 Jan. 1-4 230° + 52° 



9-13 57°- 12° 120° 0° 133° + 21° 



14-19 1 10° + 23° 130° + 33° 130° + 48° 

 25-28 132° + 31° 160° + 58° 332° + 57° 



The January- fireballs deserve more careful obser\-a- 

 tion and inquiry-. There are evidently some rich 

 showers involved, but it is ven,- difficult from the 

 limited state of our knowledge, to single out the 

 richest systems from the large number which appar- 

 ently supply our January- meteors. Apart from the 

 several radiants mentioned above, there are many 

 others fairly well defined in Aries, Taurus, Perseus, 

 Leo, Virgo, Gemini, and Ursa Major. The data 

 already collected appear to prove that the prevalence 

 of large meteors is due rather to a considerable number 

 of showers than to the special activity of two or three, 

 but the investigation can be carried still further when 

 additional materials have accumulated. 



The C.vpture Theory of Satellites. — Prof. T. J. J. 

 See's volume entitled " Researches on the Evolution 

 of the Stellar Systems" (vol. ii., "The Capture 

 Theory "), is discussed by Dr. A. C. D. Crommelin in 

 the current number of Scientia (vol. xvii., 1915.) Prof. 

 See's contention is that the planets and satellites were 

 independent of the solar system, and have never been 

 evolved from what we consider their primaries, but 

 that they have been captured from outside and made 

 to conform to their present orbits under the secular 

 action of a resisting medium. Dr. Crommelin holds 

 to the view that the matter embodied in the planets 

 was always a part of the solar system, but spread 

 out in the form of huge dust clouds, which finallv 

 condensed round certain centres. It is in support of 

 this view that the present article was written, and 



NO. 2359, VOL. 94] 



he brings forth many lines of argument wh<ch help to 

 strengthen his view. Dr. Crommelin states that his 

 conclusions do not imply any want of respect for Prof. 

 See's contributions to astronomical theorj-, for "his 

 suggestions are always stimulating and ultimately 

 help on the attainment of the truth." The new light 

 that the study of the spectroscopic binaries has shed 

 on the question calls nevertheless for a modification 

 of his views. 



Observations of the Moon. — Prof. W. H. Picker- 

 ing, in the November number of Popular Astronomy 

 (vol. xxii.. No. 9, 1914) described some interesting 

 obser\-ations on the lunar crater Aristillus, and inci- 

 dentally made some general statements which no 

 doubt have attracted attention. He points out that 

 nearly ever}-one who looks at the moon through a 

 telescope confines his attention to those regions near 

 the terminator because they furnish "striking views, 

 are easily identified, and because what is seen is easv 

 to understand." It is for this reason, he says, that 

 the impression that the moon is lifeless has so long 

 maintained its existence. According to him the only 

 time when the moon is really interesting is when its 

 surface is viewed far away from the terminator, that 

 is, during the lunar summer time, for then changes 

 are taking place, changes which are "conspicuous all 

 over the surface to any who will take the trouble to 

 watch and to study them carefully." Here, he sug- 

 gests, is the opportunity- for the amateur to come in, 

 to make his observations and drawings with care, to 

 record the times, compute the corresponding co- 

 longitudes, and to publish his results. The necessarv 

 obser\-ations do not require the highest grade of seeing 

 nor the largest telescopes. Close observation has led 

 Prof. Pickering to conclude that the moon is verv far 

 from being a dead planet, and he has advocated the 

 existence of vegetation on the moon for more than 

 twenty years ; he hopes by means of the above assist- 

 ance that his idea will gain ground, and that the text- 

 books of twenty years hence will not contain the state- 

 ment that ■■ the moon is without air, water, or vegeta- 

 tion." 



Companion to "The Observatory" for 1915. — 

 The Companion to The Observatory for the present 

 year has just come to hand, and its contents are fami- 

 liar to astronomers, both professional and amateur. 

 The substance of the matter and its arrangement 

 follows for the most part on the lines of former issues. 

 One important alteration is the page devoted to meteor 

 radiants. This year the principal radiant is given for 

 each night during the year, as well as the average 

 hourly number of meteor§ visible on a clear moonless 

 night. This information is supplied bv Mr. W. F. 

 Denning from observations made between 1866 and 

 19 14. Only two eclipses will occur during the year, 

 and these are both annular eclipses of the sun ; neither 

 will be visible in Europe. 



The Meteor-fall of Ensisheim (1492). — A reprint 

 from the Journal of the Royal Astronomical Societv of 

 Canada (September-October, 19 14) contains some in- 

 teresting historical references to the meteor-fall of 

 Ensisheim, which occurred in Alsace in 1492. These 

 notes have been brought together by Dr. C. .\. Chant 

 in the hope of clearing up several discrepancies be- 

 tween different authorities. According to Wulfing's 

 work on meteorites in collections and literature, sixty- 

 five museums are supposed to possess portions of this 

 meteorite, the original weight being 127 kg. (279 lb.), 

 of which 704 kg. have been located. Ensisheim is 

 the fortunate possessor of 54-8 kg., which is preser\-ed 

 in the town hall. 



