O. Mason & Co. Circular

Providence, Rhode Island, 1846. Near-fine. Letter folds.. Printed circular announcing improvements to "ready made belts" for machinists and manufacturers, tauting new steam power technology: "These belts are made from the best Oak-tanned Philadelphia Slaughter Leather. In the dressing of them, steam power is employed, and an entirely new method adopted, by which the leather is rendered more permanent ... They are now in use in many manufactories and machine shops". Bifolium (9.75" by 7.5"), addressed in ink manuscript on back, red ink stamps.