Hello, there are a number of significant documents that are available with Google Book service, they apparently added quite a collection of full and complete documents. One of them is of interest : The historical computation of Pi using Machin formula by William Shanks. http://books.google.com/books?vid=0A2yyrfAXNsNSwg9B-&id=axjockOKyikC&pg=PA27... and the following pages describe the digits, the formulas and results, quite interesting! and the result is : http://books.google.com/books?vid=0A2yyrfAXNsNSwg9B-&id=axjockOKyikC&pg=PA27... which contains the known error. Another document is the Differential Calculus by De Morgan: http://books.google.com/books?vid=08Wx_wKklYK4hOCS&id=95x4IrIcHrgC&printsec=... These documents are normaly quite difficult to get and see for real even in a big city with lots of libraries around... Simon Plouffe