▁the ▁end ▁of ▁the ▁Prag ue ▁Spring ▁( e . g . ▁Ji ří ▁Kol ář ). ▁Mate usz ▁Grab owski , ▁an ▁owner ▁of ▁avant - gar de ▁gallery ▁in ▁London , ▁don ated ▁art works ▁representing ▁British ▁Pop ▁Art ▁and ▁Op ▁Art ▁( e . g . ▁D erek ▁Bos h ier , ▁Br idget ▁R iley , ▁and ▁Paul ine ▁Bot y ). ▁American ▁artists ▁( e . g . ▁Sam ▁Francis , ▁Lawrence ▁We iner , ▁Barbara ▁K ast en , ▁and ▁Chris ▁Bur den ) ▁best owed ▁their ▁works ▁in ▁exchange ▁for ▁art works ▁of ▁Polish ▁artists . ▁The ▁collection ▁of ▁works ▁from ▁the ▁first ▁Const ruction ▁in ▁Process ▁[ Pol ish : ▁Kon stru kc ja ▁w ▁Pro ces ie ] ▁festival ▁don ated ▁by ▁“ Sol id ar ity ” ▁ ▁( e . g . ▁Peter ▁Down s br ough , ▁Dan ▁Graham , ▁and ▁Richard ▁Non as ) ▁en rich ed ▁the ▁representation ▁of ▁minimal ▁art . ▁ ▁In ▁a ▁symbol ic ▁gesture ▁of ▁solid ar ity ▁with ▁Polish ▁society , ▁Joseph ▁Be u ys ▁don ated ▁ca . ▁ 3 0 0 ▁art works ▁from ▁his ▁arch ives ▁within ▁the ▁framework ▁of ▁“ Pol entr ans port ▁ 1 9 8 1 ”. ▁ ▁In su fficient ▁exhibition ▁space ▁was ▁a ▁permanent ▁problem ▁of ▁the ▁Mu zeum . ▁In ▁the ▁early ▁ 1 9 7 0 s ▁a ▁tender ▁was ▁advert ised ▁for ▁the ▁construction ▁of ▁a ▁new ▁building ▁for ▁the ▁museum ▁but