▁book ▁illustr ation . ▁For ▁example , ▁he ▁illustrated ▁Charles ▁Dick ens ' ▁Great ▁Ex pect ations , ▁and ▁produced ▁four ▁colour ▁pl ates ▁for ▁a ▁ 1 9 3 5 ▁edition ▁of ▁A ▁Christmas ▁Carol . ▁In ▁addition , ▁Bro ck ▁was ▁one ▁of ▁seven ▁artists ▁who ▁contributed ▁illustr ations ▁to ▁Arthur ▁Con an ▁Do yle ' s ▁ 1 9 0 9 ▁Sher lock ▁Hol mes ▁story ▁His ▁Last ▁Bow . ▁H . M . ▁Bro ck ▁provided ▁ ▁illustr ations ▁for ▁Susan ▁C ool idge ' s ▁" What ▁K aty ▁Did ▁at ▁Home ▁and ▁at ▁School ", ▁ ▁published ▁for ▁The ▁Royal ▁Library ▁for ▁Boys ▁and ▁Girls ▁circa ▁ 1 9 1 8 . ▁ ▁Most ▁of ▁Bro ck ' s ▁illustr ations ▁were ▁for ▁classic ▁Victor ian ▁and ▁Edward ian ▁fiction . ▁He ▁also ▁did ▁a ▁great ▁deal ▁of ▁work ▁for ▁the ▁D ' O y ly ▁Car te ▁Opera ▁Company ▁for ▁whom ▁he ▁produced ▁post ers ▁and ▁other ▁advert ising ▁materials . ▁During ▁his ▁art istic ▁career , ▁H . ▁M . ▁Bro ck ▁regularly ▁exhib ited ▁his ▁draw ings ▁and ▁water col ours ▁at ▁the ▁Royal ▁Academy ▁and ▁the ▁Walker ▁Art ▁Gallery ▁in ▁Liverpool . ▁He ▁became ▁a ▁full ▁member ▁of ▁the ▁Royal ▁Institute ▁of ▁P ain ters ▁in ▁Water col ours ▁in ▁ 1 9 0 7 , ▁and ▁joined ▁the ▁newly - formed ▁Society ▁of ▁Graph ic ▁Art ▁in ▁ 1 9 2 1 . ▁ ▁From ▁the ▁ 1 9 3 0 s