Wow. I didn't expect that kind of detail, but it is certainly most welcome. The 'non-wikipedia' way of doing things sure seems to make sense. I'm a big fan of acknowledging expert authority. I also dislike the pseudonymous nature of wikipedia, but that's just because I believe that, in matters like this, one ought to stand by one's words. Thanks for the explanations! Cheers. Fil On 16 February 2012 16:41, Ken Friedman <[log in to unmask]>wrote: > Dear All, > [ excellent posts by Ken and Don snipped ] > -- \V/_ Filippo A. Salustri, Ph.D., P.Eng. Mechanical and Industrial Engineering Ryerson University 350 Victoria St, Toronto, ON M5B 2K3, Canada Tel: 416/979-5000 ext 7749 Fax: 416/979-5265 Email: [log in to unmask] http://deseng.ryerson.ca/~fil/