LIGHT. 



LITERATURE, ETC. 



459 



rial contributions during twenty-three years to 

 " Punch," he is said to have received the sum 

 of 40,000. In all the social relations he was 

 irreproachable, and his death was sincerely 

 lamented by a large circle of friends. It may 

 be truly said that "Punch" has not been itself 

 since that event. 



LIGHT. The light emitted by burning 

 nagnesium wire is rich in chemical rays so 

 nuch so that it may be used instead of sunlight 

 for the purpose of photography. The spectrum 

 of burning magnesium is exceedingly rich in 

 violet and ultra-violet rays, partly due to the 

 incandescent vapor of magnesia, and partly to 

 the intensely heated magnesia formed by the 

 combustion. So long ago as 1859 the chemical- 

 ly active power possessed by this light, com- 

 pared with that of the sun, was determined, 

 and the use of this light for the purpose of 

 photography was proposed. It was shown that 

 a burning surface of magnesium wire, which, 

 seen from a point at the sea level, has an ap- 

 parent magnitude equal to that of the sun, 

 effects on that point the same amount of chemi- 

 cal action as the sun would do if shining from 

 a cloudless sky at a height of 99 53' above the 

 horizon. On comparing the visible brightness 

 of these t^vo sources of light, it was found that 

 the brightness of the sun's disk as measured 

 by the eye, is 524 times as great as that of 

 burning magnesium when the sun's zenith dis- 

 tance is 6T 3 22'; whilst at the same zenith 

 distance the sun's chemical brightness is only 

 five times as great. Hence the value of this 

 light as a source of the chemically active rays 

 for photographic purposes becomes at once 

 apparent. The steady and equable light evolv- 

 ed by magnesium wire burning in the air, and 

 the immense chemical action thus produced, 

 render this source of light valuable as a simple 

 means of obtaining a given quantity of chemi- 

 cal illumination, and the combustion of this 

 metal constitutes so definite and simple a 

 source of light for the purposes of photo-chemi- 

 cal measurement, that the wide distribution of 

 magnesium becomes desirable. The applica- 

 tion of this metal as a source of light may be- 

 come even of technical importance. Professor 

 Roscoe, in a paper read before the British As- 

 sociation, is of opinion that a burning magne- 

 sium wire, o^the thickness of .012 inches, 

 evolves as much light as 74 stearine candles, 

 of which 5 go to the pound. In order to pro- 

 duce a light equal to 74 stearine candles burn- 

 ing for 20 hours, whereby about 20 Ibs. of 

 stearine is consumed, two and a half ounces 

 of magnesium would be required. The magne- 

 sium wire can be easily prepared by forcing 

 out the metal from a heated steel press having 

 a fine opening at bottom ; this wire might 

 be rolled up in coils upon a spindle, which 

 could be made to revolve by clock-work, and 

 thus the end of the wire, guided by passing 

 through a groove or between rollers, could be 

 continually pushed forward into a gas or spirit- 

 lamp flame, in wh'^h it would burn. 



LITERATURE AXD LITERARY PRO- 

 GRESS IX 1864. Notwithstanding the greatly 

 enhanced cost of manufacturing books, and the 

 resulting increase in the price, which, during 

 the year, advanced fully one hundred per cent., 

 the year 1864 has been remarkable for its liter- 

 ary activity. The number of works published 

 varied but slightly from the aggregate of tho 

 preceding year, but a larger proportion of them 

 were in more than one volume. The num- 

 ber of distinct publications, aside from occa- 

 sional pamphlets, reports, circulars, catalogues, 

 single sermons, etc.. was 2.028. The number of 

 reprints was comparatively small, considerably 

 less than English reprints of American books. 

 In all there were 301 foreign books, English, 

 French, German, and Italian, repnblished. Of 

 these 77 were either American translations, or 

 had received extensive revision and additions 

 from American authors, and 90 more were re- 

 printed in the foreign language in which they 

 were originally published, leaving only 134 

 simple reprints of English works. The greater 

 part of these were works of fiction. 



Of the publications of the year 25 appertain- 

 ed to military science ; 143 to the domain of his- 

 tory, of which 13 were histories of the war; 14 

 histories of particular battles or campaigns ; 53 

 narrative or didactic works on subjects apper- 

 taining to the war, though not strictly and 

 formally histories ; 23 were American local and 

 other histories, having no relation to the war ; 

 27 were histories of other countries or of the 

 United States or Colonies during or before the 

 Revolution ; 7 were historical reprints ; 8 were 

 historical magazines or transactions of histori- 

 cal societies, and 8 ecclesiastical histories. 



In the department of biography there were 

 104 publications, of which 88 were single and 

 16 collective biographies. In theology 26 works 

 were published, of which 4 were doctrinal and 

 22 polemical. Of religious works, not theolog- 

 ical, there were 139 ; of treatises on moral and 

 intellectual science, 5 ; of works appertaining 

 to physical science, 41 ; of which 15 were astro- 

 nomical, 1 a treatise on geology, 16 mono- 

 graphs on zoological topics, 1 on botany, 2 on 

 natural philosophy, and 6 on chemistry. 



The number of works on topics connected 

 with political, social, financial, and statistical 

 science was 187; philology, 10; technology and 

 mechanical science, 36 ; agriculture, 18 ; medi- 

 cal science, 54 ; legal treatises and essays, and 

 compilations of laws, 68 ; educational science, 

 43 ; geography and travel, 30 ; essays and di- 

 dactic literature, 65; poetry and music, 165; 

 novels, 242, of which only 9 were professedly 

 religious fictions; juvenile books, 428, and mis- 

 cellaneous, 19. 



Several of the works on military subjects 

 possess high merit, and do honor to their authors 

 and the literature of the country. Only 4 

 were republications, and of these, 3, viz., 

 Dnfour's " Strategy and Tactics," translated and 

 edited by Captain Craighill; Jomini's "Life of 

 Xapoleon," translated and annotated by Major- 



