▁p ist on ▁to ▁produce ▁rot ational ▁power ▁for ▁gr inding , ▁we aving ▁and ▁mill ing . ▁Although ▁a ▁c rank ▁seemed ▁the ▁obvious ▁solution ▁to ▁the ▁conversion ▁W att ▁and ▁B oul ton ▁were ▁st ym ied ▁by ▁a ▁pat ent ▁for ▁this , ▁whose ▁holder , ▁James ▁Pick ard , ▁and ▁associ ates ▁proposed ▁to ▁cross - lic ense ▁the ▁external ▁cond enser . ▁W att ▁ad am antly ▁opposed ▁this ▁and ▁they ▁circum vent ed ▁the ▁pat ent ▁by ▁their ▁sun ▁and ▁planet ▁g ear ▁in ▁ 1 7 8 1 . ▁ ▁Over ▁the ▁next ▁six ▁years , ▁he ▁made ▁a ▁number ▁of ▁other ▁improvements ▁and ▁modifications ▁to ▁the ▁steam ▁engine . ▁A ▁double ▁acting ▁engine , ▁in ▁which ▁the ▁steam ▁acted ▁altern ately ▁on ▁the ▁two ▁sides ▁of ▁the ▁p ist on ▁was ▁one . ▁He ▁described ▁methods ▁for ▁working ▁the ▁steam ▁" exp ans ively " ▁( i . e ., ▁using ▁steam ▁at ▁press ures ▁well ▁above ▁atmos pher ic ). ▁A ▁comp ound ▁engine , ▁which ▁connected ▁two ▁or ▁more ▁engines ▁was ▁described . ▁Two ▁more ▁pat ents ▁were ▁granted ▁for ▁these ▁in ▁ 1 7 8 1 ▁and ▁ 1 7 8 2 . ▁N umer ous ▁other ▁improvements ▁that ▁made ▁for ▁easier ▁manufact ure ▁and ▁installation ▁were ▁contin ually ▁implemented . ▁One ▁of ▁these ▁included ▁the ▁use ▁of ▁the ▁steam ▁indicator ▁which ▁produced ▁an ▁inform ative ▁plot ▁of ▁the ▁pressure ▁in ▁the ▁cyl inder ▁against ▁its ▁volume , ▁which ▁he ▁kept ▁as