10 



KNOWLEDGE. 



[January 1, 1900. 



he would place a mask, cutting down the field of view 

 to the area which was the largest which the great 

 36-inch refractor of the Lick Observatory could com- 

 mand. It was seen at once that, however powerful 

 the light-g'-asp of that telescope, it was quite beyond it 

 to give any idea of the structure of so large a body as 

 the Andromeda nebula, when considered as a whole. 



But there are other objects in the heavens of far 

 vaster area than the Andiomeda nebula, and to deal 

 with these in their full extent requires a wider field 

 than any telescope can cover,; they must be observed 

 directly with the unassisted eye. 



There are, then, definite branches of astronomy in 

 which the telescope is not only unnecesary but, more 

 than that, it is a hindrance. Apart, however, from 

 this, it is well to remember that the science was pursued 

 with great success for some thousands of years before 

 ever the telescope was even conceived. The length 

 of the year, the obliquity of the ecliptic, the fact 

 and amount of precession, the chief lunar inequali- 

 ties, the inclinations of the planetary orbits, and their 

 relative dimensions were all determined by direct eye 

 observation, and with a really remarkable approxima- 

 tion to the truth. Indeed, in our own day the same 

 feat has been repeated, for. as readers of Knowledge 

 will remember,* there is still living in Orissa the Hindu 

 astronomer, Chandrasekhara, who, with home-made in- 

 struments and without optical assistance, has redeter- 

 mined the elements of the chief members of the solai- 

 svstem with a most astonishing accuracy. Work of this 

 kind may not indeed " increase the sum of human 

 knowledge," for it is to repeat with very small and im 

 perfect means what is being done with the most perfect 

 appliances in the great public ob.servatories of the 

 world. But it is far from being waste time and effort 

 on that account. As a training in keenness of perception 

 and in habits of order and accuracy in obsei-vation it 

 will be of the utmost service. It is not every man who 

 climbs the ropes of the gymnasium who expects or 

 wishes to become a sailor, and so to turn the skill he 

 acquires to direct service in exactly the same line ; but 

 the strengthening of his muscles and the increase in 

 agility are solid gains to him none the less. 



Mr. Maw's wordsf on this subject also are well worth 

 quoting, and I make no apologj' for introducing 

 them : — 



"What was done in the olden times can be done in the present 

 dav. and I wish to prominently direct the attention of beginners 

 to the fact that by the employ in ent of quite simple apparatus they 

 may make observations which will hi ing home to them in a way 

 which mere reading can never do. a knowledge of many astronomical 

 phenomena which they will find to be, not only of immediate 

 interest, but of great value to them in their further studies 



" What I wish to urge, therefore, is, that those commencing the 

 stuf'y of astronomy should not be content with reading only, hut 

 should work in the open air, faithfully and systematically recording 

 their observations, however elementary these may be. I lay great 

 stress on this latter point, because unrecorded observations have, 

 as a rule, little educational value. The mere fact of describing m 

 writing any observation, however simple, which has been made is 

 of immense assistance in securing completeness and accuracy. Of 

 cours", the country offers greater facilities than towns do for this 

 out-of-door work, but there are few towns where access cannot be 

 had to some convenient site giving a fairly clear horizon and 

 Bi'.fficiently free from traffic to allow of star maps being referred to 

 without serious inconvenience. Naturally tl e beginner's fust en- 

 deavour will be to identify the brightest stars and trace out approxi- 

 mately the .onfines of the various constellations. Continuing this 

 study he will gradually acquire a knowledge of the paths followed by 



• See Knowledge for November, 1899, p. 257. 

 t Journal of ihf British Astronomical Association, Vol. X., 

 No. 1, p. 12. 



the stars in their courses from rising to setting, and obtain a clear idea 

 of the position of tlie apparent axis of this motion. As time goes on, 

 he will further notice that the constellations he has identified set 

 earlier and earlier each evening, and that other constellations 

 previously unseen will come into view on the eastern horizon. 

 Further, he will notice that the path followed by the moon in her 

 course through the sky not only differs at different parts of a 

 lunation, but varies for any given part of a lunation at different 

 seasons of the year. As his knowledge of the sky progresses, he 

 will be able to identify any bright planets which may be visible, 

 and to observe their changes of position with regard to the adjacent 

 stars, changes which he will do well to note in his sketch-book for 

 future reference and consideration. Now, the beginner who has 

 learned these elementary facts by actual observation of the sky, 

 and has subsequently by the aid of his text-books mastered the 

 reasons for what he has observed, ^"ill have made a very fair start 

 in tlie study of astronomy, and he will, I venture to think, have 

 acquired a far keener interest in the motions of the heavenly bodies 

 than he would have possessed if he had confined his attention solely 

 to hooks, or if his open-air observations liad not been of a systematic 

 character. He will also find that by the aid of some very simple 

 home-made instruments, such as a cross-staff, a rude form of transit 

 instrument, and other similar appliances, he will be able to make 

 observations which serve to still more impress upon his mind the 

 facts he has been learning. Of course, such observations must be 

 crude and wanting in accuracy, but they will, nevertheless, bo 

 found to serve a very useful educational purpose." 



It is therefore possible to become a real astronomical 

 observer without a telescope and without any outlay 

 except that necessary to procure a good star atlas. And 

 although it may appear a useless labour thus to traverse 

 for oneself the steps by which the early astronomers 

 attained a knowledge of the universe, yet the value of 

 the training involved will be immense, and the delight 

 to be derived from personally watching in progress the 

 majestic movement of the heavens, the sublimest 

 machine in creation, will soon be felt to be en- 

 thralling. 



But however great the interest that may be taken in 

 work of the kind just described, the observer will 

 be sure, ere long, to desire to do something which shall 

 be of value for its own sake, as well as for its secondary 

 effect as training. And, as has been already intimated, 

 there are certain fields, by no means too fully culti- 

 vated, which are full of interest, and for which no giant 

 telescopes are required ; indeed, in these domains, the 

 unaided eye is the ideal instrument. 



First of all, there is the observation of Meteors. The 

 past November has afforded a great deal of popular 

 interest, of a sort, in the subject of meteors. Articles 

 and letters in all the newspapers of the land excited 

 general expectation to the utmost. Everyone was 

 anxious to see a display of natural fireworks, exhibited 

 without charge, and which would utterly outdo any 

 efforts of human pyrotechny. It is perhaps no loss to 

 science that the expectation was doomed to disappoint- 

 ment. But though everyone was eager to be a spectator 

 at a magnificent display, there are very few indeed 

 who have cared to become serious observers of 

 meteors. Yet the work is of great interest and value, 

 if systematically carried out ; and the work of a single 

 observer, Mr. W. F. Denning, has supplied us to-day 

 with the most perplexing problem that still remains 

 without solution of all astronomy ; the problem of 

 " stationary," or " long enduring radiants." 



Next, comes the study of the Milky Way. Here 

 again no telescope is required. A clear sky, keen sight, 

 and great patience are the requisites. And this field 

 is also one which scarcely any observer has taken up. 

 When we have mentioned Heis, Boeddicker, Easton, 

 and Wesley, we have almost exhausted the roll of ex- 

 plorers of the Galaxy. Yet night after night its 

 mysterious convolutions are drawn out athwart the sky, 



