404 



♦ KNOWLEDGE ♦ 



[Ai-Kii. 7, 1882 



pii-s:!^'.'. If thf*y moant to go down to the undorground 

 cliitiiilx'i' tlii'V Would not have raised it at all, liut !*-t it 

 down fnim tlir Irvi-l of tln' pyramids Imsc. Hut, to Kiiy 

 truth, iiiovin;; tin- hnroo|>luij;ii» was a nKTc notliiii^ com- 

 |ian>d with tin* liftin){nf thogrrat Kolid hloukit whicli formed 

 till' pyrninid's mass. Tho on({inoc>r« who moved tlieKi- grriit 

 lilookn to thi'ir (ilnres, would not have wanted slant piLS- 

 sajjes ot the rii;lit friction slope, and all the rest of it, l>y 

 which to tuke the farco]>hnf;iiH to its ploee ; nor would 

 they have provided for unnecessary descents or ascents 

 either, hut have taken the sarcophagus from the outside 

 to its proper level, and sent it along a long level 

 passage. 



The Saliirthy lifvitrw says further — hut, what can it 

 matter what the •Saturda;/ Review says on suhjects such as 

 these ? 



A correspondent, ^Ir. .J. V. Ilodgetts, touches on the 

 a-s-sociatioii which I mentioned as existin;; between the 

 Jewish Sahliath (our Saturday) and Saturn ; labouring, 

 manifestly, under the imjiression that the point at issue 

 was the identity of the Koman gnd Saturn with the Scan- 

 dinavian deity assigned to Saturday. I5ut of course he 

 has entirely misapprehended me. It is not the god Saturn, 

 l)ut the planet Saturn, which is associated with Saturday. 

 How" Mr. Hodgetts can reconcile the clear statement of 

 Dion Cassius with his belief that the days of the week 

 were not as.sociated with the planets until the twelfth 

 century, pa.s.ses my comprehension. Dion Uassius distinctly 

 attributes the invention of the week to the Egyptians, and 

 as he wrote a thousand years before the time named, 

 there must be something wrong in Mr. Hodgett's dates. 

 In the ancient Brahminical astronomy the days are asso- 

 ciated with the same planets as among the Egyptians. See 

 Mr. Colebrooke's papers in the " Asiatic Researches." 

 Among more familiar discussions of this matter may be 

 cited liailly's " Astronomic Indienne et Orientale," and 

 Bohlen's " I):vs Alte Indien." 



Dion Ca-ssius refers to the connection between musical 

 intervals and the planets, showing that probably the old 

 ^SyP*^'"'^ '"'■'^ which Pythagoras of Samos brought to 

 Greece, included the association between the planets and 

 the days of the week ; that, in fact, all three subjects were 

 connected— planets, musical intervals, and the days of the 

 week. Lonirfellow thus poetically renders the views of 

 Egyptian astrologers on these, with them, mystical 

 matters : — 



Like I lie astrolofjcrs of old, 



In that grofit vision 1 heheUl 



tiroator and dooppr niy.*<tories. 



1 saw, witli its celestial kov.". 



Its chords of air, its frets of lire, 



The Siimian's preat jT^olian lyre. 



Ki.siiii;,' throiiph all its 80vonf<'>id bnrs, 



I''r»in earth unto the fi.veil stars. 



And thriiugh the dowy atmosphere, 



Not only could I .see hut hear 



Its wondrous and hariuonious strings 



In sweet vibmtion, sphere liy sphere ; 



From Dian'a circle liRlit and near, 



Onnard to vaster and wider rinffs, 



Whore, chanting through liis board of snowa 



.Mujestie. nioiimful Saturn poos, 



.\nd down the sunless realms of apace 



Iteverhnrntes the thunder of his bass. 



Ehrata. In th" leitcr-presa OPcompanvinj: chart of the path of 

 Mars, second column, line 10, for •'south to north" read " north 

 to .outl. • and hnc IL', for '■ north (o south." read " south to north." 

 Line I., for ■ piano of hin orbit," mid " plane of the earth'a orbit." 

 Thi. miatakPS could scarcely deceive the carefii Ircader but it is as 

 well that they nhould 1k> corrected. 



l'il()Tn(;i;Al'IIV I'OII AMATEURS. 



!!■; A. IIitoTiiKiiH, F.It.A.S. 



BEFORE leaving the historical part of tlie subject, it 

 may be in^■r«•sting to refer to the partnership which 

 was entered into between Niepce and Daguerre. The one 

 appears to have rendered no assistance whatever to the 

 other — and to Daguerre alone is due the credit of working 

 out tlie proce.ss which Was considered by the French 

 Government of so much importance, that Daguerre wa» 

 awarded a pension for life of .£210 a-year, and to Isidore 

 Xiepce* .£ 1 CO a-year — the half to revert to their widows 

 Considering the great value of the di.scovery, the sum 

 awarded was ridiculously small ; but, although the French 

 Government ajipear to have presented the discovery to the 

 world, Daguerre jiatented the process in England, and 

 must have realised a large sum I>y the sale of licen.ses. 



For many years the two proce^sses of Talbot and Daguerre 

 were e-\tcnsively used. The Talbotype, or Calotype, as it 

 was indifferently called, was more suitable for land.scapes 

 and architectural subjects than for portraits, and the 

 Daguerreotype was used almost universally for portraits, 

 and may be said to have been without a rival until 1851, 

 when Mr. F. Scott Archer presented his process to the 

 public. Sir John Herscliel, I\Ir. Bingham, M. Legray, and 

 others, had tried various means for utilising glass on which 

 to produce the negative image ; but to Mr. Archer, assisted 

 by Dr. Diamond, is due the honour of inventing a process 

 which produced the most perfect results. Mr. Archer was 

 a sculptor ; he died a few years after the publication of 

 his process, and as it then became known he was far from 

 being in prosperous circumstances, his generosity in seeking 

 no pecuniary advantage in the sale of his process, or by 

 securing it by patent, will be fully appreciated. Mr. 

 Archer did not invent the stibstance known as mllodion, 

 which consists of gun-cotton dissolved in ether and alcohol ; 

 but he made it available for photography. By adding 

 iodide or bromide, or both, to the collodion, and then, when 

 the film had set, bj' immersion in a solution of nitrate of 

 silver, the conversion of the iodide or bromide of am- 

 monia (or other similar salt) into an iodide or bromide of 

 silver, the collodion film is rendered very sensitive to light 

 The collodion process is in universal use, and for tliirtjr 

 years may be said to have had no rival. Latterly, collo- 

 dion has, to some extent, been superseded bj- gelatine. 

 We shall see wherein the processes differ in a future paper. 

 We have now given the main facts relating to the history 

 of photography. If space had permitted, we might have 

 entered into the suliject with more detail. The merest 

 glance has been given, and it has been a matter of some 

 difficulty to select the main facts. A volume could be 

 filled with the interesting details, while we have attempted 

 to tell the story in a page or two. 



The art of photography, as at present practised, is of 

 great simplicity : but, easy as it is, some experience is 

 necessary, and many failures may be expected before the 

 amateur can look with satisfaction on his work. His first 

 attempt maij he a perfect success, and so perhaps may his 

 second be, but his third attempt may be as great a failure, 

 and from want of experience he will be altogether unable 

 to account for his want of success. Much may often be 

 learnt from failures, and for the satisfaction of the be- 

 ginner he may be informeil that failures frequently occur 

 in the hands of those who have practised photography for 

 many years. No rule can be laid down for accounting for 



• Xicephoro Niepce died before the pension was granted. b»t tbo 

 imrtnorship was continued with his son Isidore. 



