Difficulties in contemporary bronze founding arising from the casting of primary metal and to remelting antique bronzes of varying compositions were recognized by Leonardo who laid down composition limits for Sn and Pb. Bronzes of the Tuscan renaissance for statuary and artillery had a characteristic composition (Cu88, Sn9, Pb2%) distinct from those of the Roman and Greek-Etruscan periods while bells were cast with about 33% tin to improve sonority. Large statues were produced by welding individual castings. Details of finishing and chemical treatments used for producing a patina are given. See <i>AATA 11-751 for pts I & II. -- AATA