Isaac Enoch Lester's patent

for the improved casting of iron - my cousin C., whose late husband's father was, if I've got it right, Isaac Enoch's son, explained the metallurgical importance of cooling the iron slowly in order to manage the crystal formation (she's a chemist). This all has to do with making better axles for Indian Railways. But what a delightful illustration. It scanned more effectively than the patent text at https://www.google.com/patents/US1093443