▁chemical ▁matter ▁( both ▁of ▁which ▁are ▁held ▁in ▁the ▁air ▁of ▁Manchester ) ▁as ▁may ▁be ▁possible '. ▁The ▁ground ▁floor ▁was ▁built ▁with ▁numerous ▁air ▁in lets ▁and , ▁although ▁his ▁client ▁felt ▁it ▁would ▁prove ▁impossible ▁to ▁exclude ▁f oul ▁air , ▁Champ ne ys ▁installed ▁j ute ▁or ▁h ess ian ▁screens ▁to ▁trap ▁the ▁so ot , ▁with ▁water ▁sp ray s ▁to ▁catch ▁the ▁sul ph ur ▁and ▁other ▁chemical s , ▁which ▁was ▁a ▁very ▁advanced ▁system ▁for ▁the ▁period . ▁In ternal ▁screen ▁doors ▁were ▁employed ▁in ▁the ▁entrance ▁hall ▁to ▁prevent ▁the ▁air ▁being ▁' f ou led ▁by ▁the ▁opening ▁of ▁the ▁outer ▁doors ' ▁with ▁internal ▁swing ▁doors ▁between ▁the ▁circul ation ▁areas ▁and ▁the ▁main ▁library ▁to ▁' pres erve ▁the ▁valuable ▁books ▁from ▁injury '. ▁By ▁ 1 9 0 0 ▁the ▁vent ilation ▁system ▁had ▁evol ved ▁to ▁include ▁electric ▁fans ▁to ▁draw ▁in ▁air ▁at ▁pav ement ▁level ▁through ▁co ke ▁screens ▁sp rayed ▁with ▁water . ▁ ▁Col lections ▁ ▁On ▁opening ▁in ▁ 1 9 0 0 , ▁the ▁library ▁had ▁ 7 0 , 0 0 0 ▁books ▁and ▁fewer ▁than ▁ 1 0 0 ▁manuscript s ▁and ▁by ▁ 2 0 1 2 , ▁more ▁than ▁ 2 5 0 , 0 0 0 ▁printed ▁volumes ▁and ▁over ▁one ▁million ▁manuscript s ▁and ▁arch ival ▁items . ▁The ▁main ▁foundation ▁of ▁the ▁library ' s ▁collections ▁acquired ▁in ▁ 1 8 9 2 ▁was