106 



KNOWLEDGE 



[May 1, 1899. 



from a photographic chart, using the Durchmusterung 

 positions of adjacent stars, is K.A. = 18' 5G"'-2, Dec. = 

 — 13" 18'. It was too faint to be photographed on 

 eighty-seven plates, from September 5, 1888, to October 

 23, 1897, including three plates in 1888, one in 1889, three 

 in 1890, eleven in 1891, three in 1892, twelve in 1893, ten 

 in 1894, twenty-one in 1895, eight in 1890, and fifteen in 

 1897. On the last of these plates, A 2845, taken at 

 Arequipa with the Bruce telescope, stars of the fifteenth 

 magnitude are shown, but the Nova is invisible. The 

 Nova appears on eight photographs taken in March and 

 April, 1898. In the description of them given below the 

 designation of the plate is followed by the date and the 

 exposure. The letter B indicates that the photograph was 

 taken at Arequipa with the eight-inch Bache telescope, 

 and I, that it was taken at Cambridge with the eight-inch 

 Draper telescope. Both of these instruments are doublets. 

 The magnitudes are estii^iated by comparison with adjacent 

 stars, and are approximate only, especially since the image 

 was near the centre of the plate only on B 21251, B 21258, 

 and B 21319. 



I 20428. March 8, 1898. Ex. 13"'. Mag. 4-7. Esti- 

 mated 0-1 fainter than — 16°5283, photometric magn. 4-6. 

 I 20500. March 14, 1898. Ex. 13™. Magn. 5-0. Esti- 

 mated 0-5 fainter than — 10"5283, and 0-4 brighter than 

 — 14''547G, photometric magn. 5-C. 



I 20G12. April 3, 1898. Ex. 16". Magn. 8'2. 

 B 21251. April 19, 1898. Ex. GO". Magn. 8-2. An 

 excellent photograph of the spectrum, 3 mm. in length, 

 and showing the lines H^, Hy, HS, Bi, lU, Jirj, and pro- 

 bably H6, bright. A broad band, wave length 4643, is also 

 bright, and narrow bright lines are seen at about 4029, 

 4179, 4238, 427G, 4459, and 453G. These lines appear to 

 be identical with the corresponding lines found in the 

 spectrum of Nova Auriga:-. A well-marked dark line 

 appears at 4060. It will be noticed that in this star, as in 

 Nova Persei, Nova Aurigae, Nova Normfe and Nova Carinse, 

 the line He is bright, while in variable stars of long period 

 this line is always dark, being probably obscured by the 

 broad calcium line H. This alone may serve to distinguish 

 between a Nova and a variable. The accompanying dark 

 lines on the edge of shorter wave length of the bright lines 

 in Nova AurigaB, Nova Normse, and Nova Carinse are not 

 visible. The line K, also, is not shown. 



I 20738. April 21, 1898. Ex. 9". Magn. 86. 

 B 21258. April 21, 1898. Ex. 62"'. Magn. 82. The 

 spectrum closely resembles that on B 21251 taken two days 

 earlier, but shows certain marked difi'erenees. The broad 

 dark line at 4060 has disappeared, and a narrow bright 

 line appears at 5005, doubtless identical with the principal 

 nebular line, 5007. The hydrogen lines appear to be 

 somewhat narrower and more intense than in the earlier 

 photograph, although the lines in the adjacent stars are 

 nearly the same in both. 



B 21290. April 26, 1898. Ex. 10'". Magn. 8-2. 

 B 21319. April 29, 1898. Ex. lO™. Magn. 8-4. 

 The region of the Nova is included on two, and perhaps 

 three, plates taken at Arequipa on October 7 and 8, 1898, 

 but not yet received in Cambridge. They will later furnish 

 important information regarding the rate of diminution of 

 the light. On March 9, 1899, the morning after the dis- 

 covery of the Nova, a faint image of it was obtained through 

 passing clouds, which showed that its photographic image 

 was about half a magnitude fainter than that of — 13°5193, 

 magn. 9-5. On the morning of March 13, 1899, the Nova 

 was examined visually by Prof. 0. C. Wendell. He found, 

 first, that its position for 1900 is E.A. = 18' 56" 12-2, 

 Dec. = — 13° 18' 16". Secondly, that it was 1-52 magn. 

 fainter than — 13^5200, and therefore 11-37 on the photo- 



metric scale. Thirdly, that its light was nearly mono- 

 chromatic with a faint continuous spectrum. This Nova, 

 therefore, like several that have preceded it, appears to 

 have changed into a gaseous nebula. This is also indicated 

 by the faint bright line at 5005, which, as stated above, 

 appeared in the photograph of its spectrum taken April 21, 

 1898. 



During the last four centuries fifteen stars have appeared, 

 which are commonly regarded as Novae. These stars are, 

 in general, near the central line of the Milky Way. Their 

 average galactic latitude is ll'^-2, while if imiformly dis- 

 tributed in the sky it would be 80*^. The region whose 

 galactic latitude is less than Q0° has an area equal to one- 

 half of that of the whole sky. Fourteen of these stars 

 appeared in this region, and only one (Nova Coronae) 

 outside of it. Nova Andromedse and Nova Centauri had 

 spectra without bright lines, and unlike other Nov®. 

 Omitting them, the average galactic latitude of the others 

 is 9°-0. The galactic latitude of Nova Coronae is 46°'8, 

 and this seems to be the only known exception to the rule 

 that all Novffi having bright lines in their spectra have 

 appeared near the central line of the Milky Way. Omitting 

 this star, the average galactic latitude of the other twelve 

 is 5^'8. The only Novre known to have bright lines in 

 their spectra are those which appeared in Corona, Cygnus, 

 Perseus, Auriga, Norma, Carina and Sagittarius. Omitting 

 the first of these, the mean galactic latitude is 4''-G. The 

 probability that such a distribution is due to accident is 

 extremely small. Edwabd C. Pickering. 



March 14th, 1899. 



AN ANGLO-SAXON "STORY OF THE HEAVENS." 



By E. Walter Maunder, f.r.a.s. 



I CHANCED on one occasion to be present at a debate 

 in a literary society on the subject of " Education." 

 The gentleman who opened the debate spent most of 

 his time in expatiating at great length, and with 

 many repetitions, on the profound ignorance of our 

 forefathers. We were reminded that up to comparatively 

 recent times even the nobility could neither read nor write, 

 and that education scarcely had an existence in this country 

 until the institution of School Boards rather late in the 

 Victorian era. I was the only person who ventured in any 

 way to call in question this sombre picture of the past, and 

 my statements on the other side were received with marked 

 incredulity. 



This little experience has suggested to me that perhaps 

 it might not be unwelcome to some readers of Knowledge 

 to have some short account of a little popular manual in 

 astronomy — popular in a two-fold sense, as being written 

 for " the unlearned," and as enjoying a wide circulation — 

 which was current in this country very nearly a thousand 

 years ago. I take astronomy as an example, partly because 

 it is the oldest of the physical sciences, and because a 

 widespread attention to it is clear evidence of a state of 

 education fairly advanced in several directions as well as 

 of an attachment to knowledge for its own sake. 



The little manual in question appears to have been 

 written during the reign of Ethelred the "Unready" 

 [i.e., the uncounselled or ill-advised), a time of violence 

 and disturbance, which can have been by no means 

 favourable for a general cultivation of science. The 

 book is an abstract in the vernacular of a Latin 

 treatise by the Venerable Bede, " De Natura Keram." 

 The author of the abstract is not known, but it has 

 been ascribed with some probability to iElfric, the 

 " grammarian," and translator of a large portion of the 



