skip to primary navigationskip to content

Professor Fox’s Cylindrical Slide Rule

last modified Oct 27, 2014 01:57 PM
Professor Fox’s Cylindrical Slide Rule

Professor Jim Wilkes and Dr Patrick Barrie

A cylindrical slide rule owned by Professor T.R.C. Fox, the first Head of the Department of Chemical Engineering at Cambridge, has been passed from Professor Jim Wilkes, Emeritus Professor at the University of Michigan, on to Dr Patrick Barrie within the CEB Department.

The slide rule was made in 1901 and is of a design patented by George Fuller in 1878. Normal slide rules have a length of 12 inches or so which limits the number of divisions and the precision of calculations. By wrapping the logarithmic scale around a cylinder, the Fuller slide rule has an effective length of 500 inches with 7250 divisions. This means that calculations can be performed to 4, sometimes 5, significant figures.

Professor Jim Wilkes was an undergraduate and started his academic career in this Department before leaving for Michigan in 1960. During his recent visit to Cambridge (October 2014), he gave an informal seminar to the Department recounting his personal memories of the time he spent here. In particular, he described how Professor Fox had a huge influence on him and was one of his "heroes". The slide rule has great sentimental value as it was one of very few personal belongings of Fox that was passed on.

The slide rule was given to Dr Barrie on condition that it is either displayed in a suitable place in the new building or looked after and then passed on to a young member of academic staff in about 25 years’ time.