I pulled this info out of a report done in 1963. <A HREF="http://ir.library.oregonstate.edu/dspace/bitstream/1957/2720/1/vol25_no6_ocr.pdf" target="_blank">http://ir.library.oregonstate.edu/dspace/bitstream/1957/2720/1/vol25_no6_ocr.pdf</A> <img src=http://img72.imageshack.us/img72/605/slide1zd5.jpg> <img src=http://img72.imageshack.us/img72/8200/slide2zp7.jpg>