January, 1915. 



KNOWLEDGE. 



11 



THE AMATEUR IN ASTRONOMY. 



By W. F. DENNING, F.R.A.S. 



It has been recently hinted that in \iew of modem 

 developments the amateur is practically out of 

 the field — or soon will be^-in astronomical work 

 and investigations. Present-day requirements are 

 such that large instruments, elaborate apparatus, 

 and refined researches, \\"ith perhaps spectroscopic 

 and photographic agenda, are absolutely needed ; 

 and, often enough, the necessary studies are most 

 laborious, requiring close application over a long 

 period, and including critical mathematical analysis. 

 These and other reasons may be suggested for the 

 opinion that the amateur is losing ground, and will 

 not take the prominent part he has done in the 

 past in aiding the progress of astronomy. 



Judging, however, from the facts and the teaching 

 of recent years, such an opinion seems quite in- 

 consistent with the real condition of things. There 

 is no doubt whatever that amateur work will 

 always be pretty much to the fore, and possibly 

 rank in value with that of the best professional 

 talent. 



The field is wide enough for each to distinguish 

 himself, the harvest of objects so extensive that 

 every kind of student may reap a share. Much the 

 same array of circumstances will continue as 

 obtained a century ago — the professional and the 

 amateur will work with increasing numbers and 

 energy towards the goal of a more complete 

 knowledge. 



It must be remembered that many of our pro- 

 fessional astronomers were amateurs at first, and 

 showed such ability and proficiency that they 

 were invited into the professional ranks. As 



examples of this, there are Barnard, Burnham, and 

 many others in America. 



If the history of astronomy be consulted, the names 

 of distinguished amateurs will be found in every 

 succeeding generation, who have effected valuable 

 work in astronomy. It is remarkable that they have 

 achieved so much, considering the obstacles often 

 impeding them, such as want of time, lack of means, 

 and suitable training. There are greater numbers of 

 the ordinary population than is generally supposed 

 who occupy themselves in astronomy as a hobby, and 

 those few among them who love the science suf- 

 ficiently to pursue it in spite of the difficulties 

 confronting them, and are impelled onwards by 

 success, usualh' comprise men of real ability and 

 aptitude for the work. They have naturally risen 

 above the rank and file, and represent " the sur- 

 \-ival of the fittest." 



The amateur can do good work in nearly every 

 department, but there are some which apparently 

 suit his capabilities and inclinations in a special 

 degree. These I need not mention, as they are 

 sufficientiv ob\-ious to everyone acquainted mth the 

 subject. To amateurs of means of course there is 

 hardly any limit to the extent of the valuable 

 ser\ices they may render the science. Lord Rosse, 

 James Xasmyth, Robert Carrington, WilUam LasseU, 

 and quite a host of others will be well remembered. 

 The literary work of certain amateurs has also 

 had a great influence : we may mention the books 

 of Dick (see Figure 15), Proctor, Flammarion, 

 Smyth, Chambers, J. F. W. Herschel, Agnes Clerk, 

 Webb (see Figure 16), and others. 



{To be continued.) 



SOCIETIES. 



THE LIXNEAN SOCIETY.— At a meeting of the Lin- 

 nean Societ\-, held on Thursday, December 1/th, 1914, 

 Mr. iliUer Christy, F.L.S., exhibited a remarkable gall, 

 which he beUeved to be new to this countn*. It is in the 

 nature of a " Witches' Broom," but appears on Salix 

 fragilis ; whereas no " broom " of the kind has hitherto 

 been recorded on any species of willow in this country. It 

 appears ia great abundance on all trees of the species named 

 growing in proximity'. According to Professor Nalepa, 

 it is due to a gaU-mite, Eriophyes triradiatus, but not im- 

 probably a parasitic fungus may assist. 



So far, the gaU is confined apparently to a Umited area 

 within a radius of, say, twelve or fifteen miles around 

 London. Mr. Christ\' has seen it or had it reported to him 

 from Walthamstow, Chingford, Romford, Dagenham, and 

 from Eltham and other places in Kent ; and he has been 

 unable to hear of it ha\-ing been seen anywhere earlier than 

 three or four years ago. It is unnoticed, he beUeved, in 

 any work on the plant-gaUs of Britain. 



The gall seems to appear only on Salix fragilis ; never on 

 Salix alba var. caeridea. This is fortunate, as the former is 

 a tree of almost no economic importance, while the latter 

 is of high value. 



The gall is remarkable in that it appears on the female 

 flower, which develops during summer, till it resembles a 



bunch of moss, of an oUvaceous green colour, from two to 

 eight inches in length, hanging from a small tv\dg. The 

 bunch consists of hundreds, perhaps thousands, of abnormal 

 flowerets. 



In the course of the mnter the gaU or broom shrivels 

 and becomes black, but continues to hang on the trees 

 through the following summer, presenting a most striking 

 appearance. 



ROYAL INSTITUTION.— The following are among the 

 lectures to be given at the Royal Institution before Easter : 

 Professor WiUiam J. Pope, two lectures on Colour Photo- 

 graphy — Scientific Applications : (1) " Photographic Appre- 

 ciation of Colour in ^Monochrome " ; (2) " Photography 

 in Natural Colours." Professor Sir James G. Frazer, t\vo 

 lectures on " The BeUef in ImmortaUty among the Poly- 

 nesians." Dr. Henry G. PUmmer, three lectiires on Modem 

 Theories and Methods in Medicine. Dr. Chalmers Mitchell, 

 three lectures on Zoological Studies — War and Evolution : 

 (1) " Nations as Species " ; (2) " Struggle of Species " ; 

 (3) " Struggle of Nations." Professor Sir J. J. Thomson, 

 six lectures on " Recent Researches on Atoms and Ions." 

 The Friday evening meetings will commence on January 

 22nd, when Professor Sir James Dewar will deUver a 

 discourse on " Problems of Hydrogen and the Rare Gases." 



