▁By ▁the ▁end ▁of ▁the ▁week , ▁British ▁strength ▁stood ▁at ▁over ▁ 1 6 , 0 0 0 ▁men . Mc G ar ry , ▁pp . ▁ 1 6 7 – 1 6 9 ▁Their ▁fire power ▁was ▁provided ▁by ▁field ▁art illery ▁which ▁they ▁position ed ▁on ▁the ▁North side ▁of ▁the ▁city ▁at ▁Ph ib s borough ▁and ▁at ▁Tr inity ▁College , ▁and ▁by ▁the ▁pat rol ▁vessel ▁Hel ga , ▁which ▁sa iled ▁up ▁the ▁L iff ey , ▁having ▁been ▁sum mon ed ▁from ▁the ▁port ▁at ▁King st own . ▁On ▁Wed nes day , ▁ 2 6 ▁April , ▁the ▁guns ▁at ▁Tr inity ▁College ▁and ▁Hel ga ▁sh elled ▁Liber ty ▁Hall , ▁and ▁the ▁Tr inity ▁College ▁guns ▁then ▁began ▁firing ▁at ▁re bel ▁positions , ▁first ▁at ▁Bol and ' s ▁Mill ▁and ▁then ▁in ▁O ' Con nell ▁Street . ▁Some ▁re bel ▁command ers , ▁particularly ▁James ▁Con n olly , ▁did ▁not ▁believe ▁that ▁the ▁British ▁would ▁shell ▁the ▁' second ▁city ' ▁of ▁the ▁British ▁Empire . F oy ▁and ▁Bart on , ▁p . ▁ 1 8 1 ▁ ▁The ▁principal ▁re bel ▁positions ▁at ▁the ▁G PO , ▁the ▁Four ▁Cour ts , ▁Jacob ' s ▁Factory ▁and ▁Bol and ' s ▁Mill ▁saw ▁little ▁action . ▁The ▁British ▁surrounded ▁and ▁bomb arded ▁them ▁rather ▁than ▁assault ▁them ▁directly . ▁One ▁Vol unte er ▁in ▁the ▁G PO ▁re called , ▁" we ▁did ▁pract