UNDULATORY FORCES. LIGHT. 



[ARTIFICIAL LIGIIT. 



poroeUin, *o. We my, however, possibly orr in our 

 notions with roapoct to the state of icicnoo in the early 

 get. But fow works of those times hare boon handed 

 down; ami tin- divtruetion f the Alexandrian library, 



may have entirely shut fnun our view the results o 

 vwtigktions which might possibly hare rivalled the 



pro- 



duct ions of our own age. Whilst, therefore, we may rejoice 

 in that which we possess, we should do so with modesty ; 

 for as long as science is studied, we shall ever II.-M 

 acknowledge, that some of the ancients Euclid and his 

 co-workers have done more to assist us in the means of 

 pursuing exact investigations, than any of their successors. 



CHAPTER III. 

 ARTIFICIAL ILLUMINATION. 



WE shall now proceed to consider some of the applica- 

 tions of light, commencing with that of Artificial 

 Illumination ; a paper on which has been furnished by 

 .1 Ki'ntloman highly conversant with the subject.* 



After the article on Artificial Illumination, we shall 

 direct the attention of our readers to the interesting 

 subject of Photography ; and endeavour to put them in 

 possession of both the practice and theory of that 

 singular application of light. 



ARTIFICIAL ILLUMINATION. 



Historical Notice, The advantages of artificial light 

 are so numerous and important, that they must have 

 claimed attention from the very earliest period of 

 history: in fact, long before man had commenced his 

 work of civilisation, the light of the cheerful fire must 

 have been a source of comfort and security; for, per- 

 haps, nothing assists so powerfully in dispelling the 

 gloom of darkness, and banishing the terrors of night, 

 as the lustre of a cheerful fire. And then, as civilisa- 

 tion advanced, the usefulness of artificial light must 

 have been perceived in a thousand ways. True, it 

 might at first have been employed merely as a luxury 

 among the rich ; but, in process of time, it became a 

 necessary even with the poor ; and were wo now to de- 

 prive man of all means of obtaining artificial light, the 

 consequences would be terrible we should cripple his 

 energies and impoverish his intellect a great portion of 

 his time would be lost to him every industrial occupa- 

 tion would be hindered the very safety of the com- 

 munity would be endangered and, in fact, the wealth 

 and commerce of every nation would be seriously 

 affected. These considerations endow our subject with 

 an interest of no ordinary character ; and we may truly 

 say, that few inquiries would furnish so profitable a 

 result as a complete history of Domestic Illumination, 

 " tracing its gradual development from the solitary 

 watch-lantern, graven on the pyramid, through the 

 graceful but very imperfect lamps of the Greek and 

 Roman period, as exhibited in our museums, and the 

 clumsy contrivances of the middle ages, up to the pro- 

 ductions of ui"<l> MI times, satisfying the demands l><>tli 

 of taste and science. In such a narrative might be 

 shown the progress of light, in the literal signification 

 of the word, by a careful examination of the various 

 forms in which it has been at different tunes employed 

 as lamp, l:iiil-rn, torch, flambeau, falot or cresset, 

 candle, and gas whether for the celebration of religious 

 nonics, for increasing domestic comfort, adding to 

 the security of the streets, or forming a beacon to guide 

 the mariner at night. It would be, at the same time, a 

 history glancing at the advancement which the improve- 

 ments in illumination havo given to the social condition 

 of mankind, and at the advantages which science has 

 derived from the study of this subject." Besides which, 

 there would be mixed up with such an historical account 

 many of the fanciful hypotheses and highly poetical 

 conceits in reipect of the nature of fire, which nave at 

 various times occupied the attention of man. 



|Vrlia|>< the earliest source of artificial light was the 

 wood lire, blazing in the recesses of the forest, or in tin- 

 hut of the savage ; and then, as experience led to the 



A* rone of the faru Included in the original harp hem already dU- 

 uaed. the editor hi omitted inch, and has node addition! on nuturi 

 wtteh hart OOB* under hla own obarrrauon. 



discovery of the fact that different kinds of wood burn 

 with different degrees of splendour, it must have been 

 perceived that certain vegetable substances might be 

 employed, in preference to others, as a means of obtain- 

 ing light. In this way a splinter of pine, the resinous 

 bark of a tree, or even the oily kernel of a nut, might 

 early have been resorted to for such a purpose ; indeed, 

 we are told that the inhabitants of Tortuga had long 

 used the wood of yellow sandal ; those of New England 

 made choice of a resinous splinter of pine ; the natives 

 of British Guiana selected the wood of an amyris ; and 

 in Otaheite, the candle was a row of nuts fastened upon 

 a skewer. Again, accident must soon have taught man- 

 kind that the resinous exudations of trees, the fat of 

 animals, and the bitumen and naphtha of the mineral 

 kingdom, were not only highly combustible, but that, 

 while burning, they were also highly luminous. Having 

 learnt this fact, it required but little ingenuity to sug- 

 gest the use of some porous material upon which the 

 combustible might be smeared, or into which it might be 

 dipped, before it was burnt. In this way the torch, the 

 candle, and the lamp, were doubtless invented. 



The first authentic evidence that we have of the use 

 of candles is furnished by Pliny in the 13th Book of his 

 Natural History. He there says, in speaking of the lost 

 books of Numa, that when Terentius, the scribe, dis- 

 covered the sepulchre of the king, he found in it a parci-l 

 of books tied round in every way with candies, after the 

 manner of the cere-cloth. This story is quoted from 

 Piso, Tuditanus, Varro, Antias, and others : it is 

 repeated by Livy, who states that the candles were two 

 in number. Now as Numa was the successor of Romu- 

 lus, and reigned about 700 years before the birth of 

 Christ, it is evident that candles were used in the 

 earliest days of Roman history : judging, also, from the 

 use to which they had been put, it would appear that 

 they were composed of string or rope covered with some 

 combustible, perhaps pitch or wax. It is to be re- 

 gretted, however, that Pliny has not given us a more 

 particular account of the construction of those candles ; 

 indeed, he has not informed us how any of the candles 

 of his time were manufactured ; he merely alludes to 

 the subject incidentally. Thus, in his chapter on Wil- 

 lows, he says that the pith of the brittle rushes, which 

 grow in marshy places, is used for making wicks for 

 watch-candles and funeral-lights, to burn by a dead 

 body while it lioth above the ground ; and, in a sul 'se- 

 quent chapter on Flax, he states that the part of the 

 reed which is outermost and nearest to the peel, or rind, 

 is called tow, and is good for nothing but to make lanip- 

 matoh or caudle-wick: nothing whatever being said 

 respecting the material which was put alxmt' those wicks. 

 The inference, however, is that the watch-candles in 

 Pliny's time were like our rushlights, mid that the 

 others wore similar to the pitched rope which we em- 

 1<1"V, after the fashion of a torch, for common illumi- 

 nating purposes. Fosbrooke informs us, in his Em 

 ptditi af Aiititfiiitirt, that the candles of the ancients 

 were sometimes made of the leaves of the papyrus 

 covered with wax or tallow : and he remarks, that ' 

 moil kitchen-stuff was used for such purposes as far 

 K-K-k a the days of Augustine. A proof of this is to l>e 

 found in the writings of Apulcius, who speaks of two 

 kinds of candles namely, the crrci, or wax, and the 

 lebacti, or tallow. 



During the middle ages, wax was extensively employed 



