Here's a start from a Goggle search "Niter and Mining Bureau", go to page 477 @

http://books.google.com/booksid=qdcBAAAAMAAJ&pg=PA477&lpg=PA477&dq=%22Niter+and+Mining+Bureau%22&source=bl&ots=EfVCn5GlSZ&sig=NdG5hFSOp5l4Anq4ui0WcnxoOnM&hl=en&ei=WoWQS9XiCpKcsgOkk4H9Aw&sa=X&oi=book_result&ct=result&resnum=6&ved=0CBgQ6AEwBQ#v=onepage&q=%22Niter%20and%20Mining%20Bureau%22&f=false