February 4, 1892] 



NA TURE 



33^ 



facturer feels regret and pain at seeing work inefficiently per- 

 formed, our national system of education will be incomplete. 



All the labour now expended in watching work in progress, 

 and in testing it when completed to see that it has not been 

 scamped, is so much withdrawn from the real business of pro- 

 duction. Every rise, therefore, in the standard of thoroughness 

 of a community means the saving of waste labour. But far 

 greater than this will be the actual increase in the productive 

 power when each gives his best endeavours to his share of the 

 world's work. And greatest of all will be the gain in the 

 nation's happiness, since he who works with his whole soul 

 knows no drudgery. 



The lesson to be taught is no new one — it was set many 

 centuries ago; and hundreds of thousands a year will be well spent 

 if the County Councils can succeed in bringing home to the hearts 

 of us all this — " Whatsoever thy hand findeth to do, do it with 

 thy might." 



PHOTOGRAPHY AS A BRANCH OF 

 TECHNOLOGY^ 



'X'HE invitation conveyed to me by your Council, to assist in 

 -*■ promoting a scheme of photographic technical education 

 of a more complete character than that provided by the ele- 

 mentary schools, is in such complete accord with the principles 

 which I have always held, and which I have occasionally pro- 

 mulgated through other channels, that I felt it an almost 

 imperative duty to respond to the invitation in spite of the 

 numerous other claims upon my time. For I believe that if the 

 Photogiaphic Society will throw itself with zeal into some well- 

 organized scheme in this direction a great benefit will be con- 

 ferred upon the cause of technical education in this country. I 

 will even go so far as to express the belief that a work of 

 national importance may be accomplished. 



It may perhaps appear as preposterous to dwell upon thfe im- 

 portance of photography before the members of this Society as 

 it would be for a merchant to address the Chamber of Com- 

 merce on the importance of trade, or for a financier to lecture to 

 an Institute of Bankers on the importance of banking. Never- 

 theless, it is a common experience that those who are actively 

 engaged in the prosecution of some special kind of work often 

 take a narrow view of their own labours ; they have no time to 

 take a bird's-eye view of the whole subject, and an independent 

 outsider may sometimes do good service by gathering up the 

 odds and ends of scattered observations and fitting them into 

 their right positions in the general plan. If any justification is 

 required from me for addressing a Society composed so largely 

 of photographic experts, I need only plead that as a teacher of 

 technical chemistry I have felt it necessary to give full recognition 

 to the claims of photography as an important branch of tech- 

 nology. It can no longer be ignored that photography has 

 penetrated the arts and sciences to an extent that has raised it to 

 an exalted position among technical subjects, and as such it has 

 not yet received its proper recognition in this country. From 

 the very dawn of its discovery the importance of its applications 

 was foreseen, although it is only in our own time that the 

 realization of this importance is being witnessed. We need not 

 commit ourselves to the extravagance of Paul Delaroche, the 

 artist, who, during the excitement caused by the revelation of 

 the Daguerreotype process, is said to have declared : " Painting 

 is dead from this day ! " The art of the painter has not been 

 killed, but it may fairly be claimed that it has been aided by 

 photography ; the art of the engraver has been revolutionized 

 by its means. The prophetic utterance of a writer in the 

 Edinburgh Revirw for January 1843 has been fulfilled : — 



" The art of Photography or Photogeny, as it has been called, 

 is indeed as great a step in the fine arts as the steam-engine was 

 in the mechanical arts ; and we have no doubt that when its 

 materials have became more sensitive, and its processes more 

 certain, it will take the highest rank among the inventions of 

 the present age." 



All who are familiar with modern photographic methods will 

 admit the truth of this prediction ; the materials have been 

 rendered more sensitive and the processes more certain. The 

 sensitiveness has been increased to a degree that would 

 probably astonish the writer of the passage quoted, and the 



' An Address to the Photographic Society 

 Meldola, F.R.S. 



NO. Tt62. vol. 45] 



Februarj' 2, by Prof. R. 



certainty of the processes is such that the amateur photographer 

 exists by thousands. It is perhaps this last circumstance which 

 is responsible for the identification of photography in the public 

 mind with the taking of portraits and landscapes. These are no 

 doubt very important applications of the subject, but photo- 

 graphy is not synonymous with portraiture and the taking of 

 scenery; if we allow this view of the subject to prevail, it 

 cannot but have the effect of narrowing down the general estimnte 

 of its importance, and of thus injuring its claim to take high 

 rank among technical subjects. We are here, I imagine, to 

 procla'm the far-reaching importance of our subject. Everyone 

 knows with what beautiful effect the photographer can reproduce 

 a portrait or a piece of scenery, but what is not so generally 

 known to the public at large is the enormous service that 

 photography has rendered to other branches of science. If 

 dwell therefore upon this application of the subject, it is not for 

 the purpose of depreciating its application to art, but rather for 

 the purpose of exalting both aspects. 



The modem dry plate has insinuated itself into everybranch 

 of practical science; whenever a phenomenon of a temporary 

 character has to be registered with absolute accuracy — where 

 the human eye fails, owing to the faintness of the object, or the 

 rapidity with which the phenomenon occurs, there the aid of 

 the dry plate is invoked. The application of photography to 

 astronomy has, as is well known, relieved the eye of the 

 astronomer and curtailed the work of the observatory to an 

 extent bordering on the marvellous. A faint nebula, which by 

 eye observation may take many years of wearying labour to 

 represent in the form of a drawing, in the course of a few hours 

 improses its image in all its fineness of detail on the photo- 

 graphic plate— a memorial for future ages of the true form of 

 the nebula at the time of its being photographed. Stars which 

 appear as points of lights in the telescope are shown by the 

 photographic plate to be small nebul3e,and stars and nebulae which 

 have altogether eluded the most powerful telescopic search im- 

 press themselves on the sensitive film. All this and much more in 

 the same direction is such familiar knowledge now that it is only 

 necessary to mention the facts, nor need I remind you how the 

 photographic plate is being utilized for the photo-astrographic 

 survey of th* heavens, and in astronomical spectroscopy for the 

 permanent registration of the solar spectrum and the spectra of 

 the stars. The "Draper Memorial" is one of the latest ex- 

 amples of the utility of photography in the observatory ; it is no 

 exaggeration to say that one of the grandest problems of 

 modern science — the question of stellar evolution — will be ren- 

 dered capable of scientific discussion by this application of the 

 gelatino-bromide film. The modern astronomical observatory 

 is in fact equipped for photographic work quite as much as for 

 observational work, and the photographer has become as 

 necessary as the observer. 



In physics and in chemistry also the photographic plate has 

 been added to the weapons of research. Here it has been used 

 to record phenomena which occur with such rapidity as to elude 

 visual perception. What would the Edinburgh Reviewer of 1843 

 have thought of the possibility of photographing a soap film in 

 the act of breaking, or a liquid drop in the act of falling? Yet, 

 as you all know. Lord Rayleigh and Mr. Boys have succeeded 

 in doing this. Or take again the application of the sensitive 

 plate to the elucidation of the phenomena of gaseous explosions 

 by Prof. Oettingen who, by using a rapidly rotating dry plate, 

 was enabled to show the intermittent character of the flash pro- 

 duced by the explosion of hydrogen and oxygen. Profs. 

 Liveing and Dewar have also succeeding in photographing the 

 spectrum of a mixture of exploding gases. In spectrum 

 analysis, in fact, the services which have been rendered by 

 photography cannot be over estimated. The astronomer, the 

 physicist, and the chemist must have for reference complete and 

 accurate charts of the spectra of the chemical elements. The 

 early maps of Bunsen and Kirchoff, and the splendid " Spectre 

 Normale " of Angstrom were drawn by eye observation after 

 years of laborious work, and with injury to the eyesight of the 

 observers. These maps are now produced by photography with- 

 out any tax upon the eyesight, and with an amount of detail 

 that renders the early maps— executed with such painful labour 

 — but mere skeletons as compared with their photographic re- 

 presentatives. The spectra can moreover be compared fai more 

 readily and with much greater accuracy by the photographic 

 method. The method o{ eliminating the lines in the spectrum 

 of one element, due to the presence of a trace of some other 

 element as an impurity, which we owe to Prof. Norman Lockyer, 



