I got an order for my book from an engineer in my own country who had studied physics. She wrote in that message that she had not only been taught SI but also ifp during her training. I found this strange as I always assumed that these units are almost never used in that branch of science. I have sent information to her about how to order the book and I have asked her why she had to learn to use these units at all. It may be that she is an engineer in a 'contaminated' branch like aviation or computer hardware engineering. I am looking forward to receive an answer.
Han Historian of Dutch Metrication, Nijmegen, The Netherlands
