Con nel ▁and ▁Kennedy ▁had ▁over t aken ▁the ▁Murray s ▁as ▁Manchester ' s ▁biggest ▁cot ton ▁sp inners . ▁ ▁In ▁ 1 8 3 3 ▁A ▁& ▁G ▁Murray ▁were ▁employ ing ▁only ▁ 8 4 1 ▁people , ▁a ▁reduction ▁in ▁work force ▁George ▁Murray ▁attributed ▁to ▁" re cent ▁improvement ▁in ▁the ▁firm ' s ▁mach in ery ". ▁ ▁In ▁ 1 8 4 2 , ▁Dou bling ▁Mill ▁and ▁Fire proof ▁Mill ▁were ▁built ▁on ▁the ▁corner ▁of ▁Red hill ▁Street ▁and ▁Beng al ▁Street . ▁Dou bling ▁Mill ▁is ▁five ▁store ys ▁high ▁with ▁an ▁engine ▁house ▁designed ▁to ▁contain ▁a ▁ 4 0   hp ▁beam ▁engine . ▁Dou bling ▁Mill ▁was ▁used ▁for ▁dou bling ▁– ▁the ▁process ▁of ▁combining ▁two ▁or ▁more ▁lengths ▁of ▁y arn ▁into ▁a ▁single ▁thread ▁– ▁cot ton ▁produced ▁in ▁the ▁company ' s ▁earlier ▁mill s , ▁giving ▁the ▁mill ▁its ▁name . ▁Fire proof ▁Mill , ▁again ▁as ▁its ▁name ▁suggests , ▁was ▁designed ▁to ▁be ▁fire proof ▁by ▁using ▁cast - ir on ▁be ams ▁and ▁columns ▁rather ▁than ▁tim ber ; ▁it ▁was ▁the ▁first ▁mill ▁in ▁the ▁mill ▁complex ▁to ▁have ▁been ▁built ▁to ▁resist ▁fire . ▁The ▁mill ▁is ▁four ▁store ys ▁high ▁and ▁may ▁have ▁been ▁used ▁as ▁a ▁w are house . ▁The ▁two ▁new ▁mill s ▁were ▁also ▁linked ▁to ▁the ▁original ▁complex ▁by ▁t unn els ▁under ▁Beng al ▁Street . ▁The ▁firm ▁" double d ▁more