Show PUSHING ORES FOR microscopic STUDY inter engineers 81 of the department of the interior assigned to the lal La lakee kec experiment station of the bureau of mines salt city utah h have the metallurgical ork in connection with koett lugof ing of that t station performed experimental work in the polish anif 0 ores 01 for microscopic ro study and photographing at high chrom h athons using g plates the use of auto this th i s me plated lates makes akes rendition in natural colors possible and will daily be ue of great value I 1 in i n photographing minerals espe at Polish polished high agn icat ions it is a dif licit t matter to prepare aral brals do cd surfaces es of ores in such a manner that the harder minu dot stand staid out in too great relief from the softer ores to prevent sharp focusing of both at high magnifications experimental peri mental work along these lines is being carried on as opportunity port unity permits |