▁of ▁him ▁in ▁ 1 9 9 2 , ▁has ▁argued ▁that ▁W att ' s ▁disc ou ragment ▁of ▁Mur do ch ' s ▁work ▁with ▁high ▁pressure ▁steam ▁on ▁his ▁steam ▁road ▁locomot ive ▁experiments ▁delayed ▁its ▁development : ▁W att ▁right ly ▁believed ▁that ▁bo ilers ▁of ▁the ▁time ▁would ▁be ▁unsafe ▁at ▁higher ▁press ures . ▁ ▁W att ▁pat ented ▁the ▁application ▁of ▁the ▁sun ▁and ▁planet ▁g ear ▁to ▁steam ▁in ▁ 1 7 8 1 ▁and ▁a ▁steam ▁locomot ive ▁in ▁ 1 7 8 4 , ▁both ▁of ▁which ▁have ▁strong ▁claims ▁to ▁have ▁been ▁invent ed ▁by ▁Mur do ch . ▁The ▁pat ent ▁was ▁never ▁cont ested ▁by ▁Mur do ch , ▁however , ▁and ▁B oul ton ▁and ▁W att ' s ▁firm ▁continued ▁to ▁use ▁the ▁sun ▁and ▁planet ▁g ear ▁in ▁their ▁rot ative ▁engines , ▁even ▁long ▁after ▁the ▁pat ent ▁for ▁the ▁c rank ▁exp ired ▁in ▁ 1 7 9 4 . ▁ ▁Mur do ch ▁was ▁made ▁a ▁partner ▁of ▁the ▁firm ▁in ▁ 1 8 1 0 , ▁where ▁he ▁remained ▁until ▁his ▁ret irement ▁ 2 0 ▁years ▁later ▁at ▁the ▁age ▁of ▁ 7 6 . ▁ ▁Leg acy ▁ ▁As ▁one ▁author ▁states , ▁James ▁W att ' s ▁improvements ▁to ▁the ▁steam ▁engine ▁" convert ed ▁it ▁from ▁a ▁prime ▁m over ▁of ▁marg inal ▁efficiency ▁into ▁the ▁mechanical ▁work hor se ▁of ▁the ▁Indust rial ▁Revolution ". ▁The ▁reality ,