PHOTOGRAPHY UNDERGROUND.

New Zealand Times, Volume XXXII, Issue 4961, 15 February 1877, Page 3

PHOTOGRAPHY UNDERGROUND.

We have to record (says the Bh'niirigliam Post) a novel and interesting application of this most useful art. .A few daysago, we believe for the first time, an experiment was success-' fully made for the; purpose of obtaining, an accurate picture of some undeground workings in a coal mine, the process being effected by means of the oxyhydrogen. light, generally known as- the lime light,- in combination -with magnesium riband'in combustion; • The scene -of i the explosion was the Bradford Colliery, Bentley, near Walsall, where a few 'days ago Mr. Frederick Brown, of Walsall, accompanied by| Mr. Chidley, representing : the ! firm of Messrs. 'Duignanj and . Co., ,solicitors' of. that town, attended at : the mine for the -purpose -of obtaining- representations of" certaini portions of the underground workings '. to illustrate a question of practical mining which is incidental to a' litigation ' respecting that colliery, and having made ~ some - preliminary experiments with magnesium- ligh't, came to the 1 conclusion that photography would be perfectly possible under conditions which exclude sunlight altogether. 1 Upon the following day Mr. Brown, attended by one of the proprietors of, the mine and the deputies, successfully obtained pictures of the portions" of thymine indicated by Mr. Chidley." The photographs, as finished, are not only in themselves valuable for the purposes of evidence for which they were required, but, when viewed in the stereoscope, form perfectly accurate delineations of the places from which they were taken, and,, indeed, without an explanation that they had been taken altogether by artificial light, the ordinary observer would suppose them to have been produced by the action of the sun in the ordinary way. The process occupied for each picture from twenty-five minutes to half-an - hour, while the sensitive • plate was under 5 the action of the light; One of the principal technical obstacles which Mr. Brown had to encounter in the chemical portion of the process was that the ordinary-wet place, although so : much more rapid- in its action, would not retain its moisture for the lengthened time of exposure rendered necessary under the altered conditions of light and the well-known increased temperature in mines ; but this difficulty was, after repeated experiment, admirably overcome by a chemical formula which Mr.. Brown was fortunately able to,devise; to meet the special emergency. The'diffi-' culties of focussing arising from cramped position in the mine were, of course, merely mechanical, but consumed much time to overcome. ■ The result appears important in many ways, as suggesting in future the possibility as well as the propriety of photographing the interior of, mines '. after ■ accidents; and in the course of litigations and. the like, for .the edification of those'who have not had the op-

Pprtunitj_of Jaating.thespdtsi'.'aßd- yet .might have to decide questions respecting them The possibility also of .introducinga. powerful and steady light completely undeccontrol, which may be fed from the surface, by means of flexible tubing, and which would enable a light rivalling that of day to be:sent.into dangerous places from a convenient and safe distance, appears to us to- open a pathway to very important practical application.