▁design : ▁an ▁area ▁of ▁mountain ▁slope ▁was ▁cleared ▁and ▁smooth ed ▁with ▁a ▁wat ert ight ▁surface ▁with ▁a ▁simple ▁can opy ▁supported ▁by ▁pill ars ▁or ▁rid ges . ▁The ▁sides ▁of ▁the ▁structure ▁were ▁closed , ▁but ▁the ▁top ▁and ▁bottom ▁edges ▁were ▁left ▁open . ▁At ▁night s , ▁the ▁mountain ▁slope ▁would ▁cool ▁and ▁in ▁the ▁day ▁mo ist ure ▁would ▁collect ▁on ▁and ▁run ▁down ▁the ▁smooth ed ▁surface . ▁Although ▁the ▁system ▁apparently ▁worked , ▁it ▁was ▁expensive ▁and ▁K la ph ake ▁finally ▁adopted ▁a ▁more ▁compact ▁design ▁based ▁on ▁a ▁m ason ry ▁structure . ▁This ▁design ▁was ▁a ▁sugar lo af - sh aped ▁building , ▁about ▁ ▁high , ▁with ▁walls ▁at ▁least ▁ ▁thick , ▁with ▁holes ▁on ▁the ▁top ▁and ▁at ▁the ▁bottom . ▁The ▁outer ▁wall ▁is ▁made ▁of ▁concrete ▁to ▁give ▁a ▁high ▁thermal ▁capacity ▁and ▁the ▁inner ▁surface ▁was ▁made ▁of ▁a ▁por ous ▁material ▁such ▁as ▁sand stone . ▁According ▁to ▁K la ph ake : ▁ ▁Tra ces ▁of ▁K la ph ake ' s ▁cond ens ers ▁have ▁been ▁tent atively ▁identified . ▁ ▁In ▁ 1 9 3 3 , ▁the ▁Naz i ▁Party ▁assumed ▁power ▁in ▁the ▁after math ▁of ▁decl ine ▁of ▁the ▁We imar ▁Republic . ▁ ▁K la ph ake ▁was ▁an ▁individual ist ▁and ▁quietly ▁ant agon istic ▁towards ▁the ▁Naz i ▁regime , ▁but ▁he ▁kept ▁his ▁views ▁to ▁himself ▁and ▁he ▁was ▁not ▁much ▁trouble d