Slide rules and other mathematical instruments
The saying that a prophet has no honour in his own country is well
exemplified in the case of the Slide Rule and its invention. For
many years this useful instrument was greatly undervalued in
England, the country in which it was invented, and even as late as
1850 it was very little known. Yet as De Morgan has put it
"for a few shillings most persons might put as much power of
calculation in their pockets many hundred times as contained in
their heads and the use of this instrument is attainable without
any knowledge of the properties of logarithms on which principle
R. T. Gunther, Historic Instruments for the Advancement of Science Oxford,
The invention of the slide rule.
There was, at the time, considerable controversy about who
invented the slide rule. Strong words were traded between the
protagonists in the introductions of various books.
- Oughtred's Circle of proportion.
William Oughtred (1574-1660) wrote a number of
important mathematical works including Clavis
Mathematicae (Key to Mathematics), London (1631) and ``The Circles of Proportion and
the Horizontal Instrument" London (1632).
Isaac Newton's slide rule.
Isaac Newton used slide rules to solve polynomial equations.
- Non-logarithmic slide rules.
Slide rules and logarithms are synonymous.
Thus, it may come as
a surprise to discover that to produce a slide rule capable of
multiplying two numbers is is not necessary to use logarithms.
- Slide rules for special purposes.
Many slide rules are designed for special
purposes. How is this done?
- Mathematics Galore!
In my book, Mathematics Galore!
co-authored with Prof.
Chris Budd, University of
Bath, Chapter 9 - Doing the sums - is an explanation of
logarithms and, of course, their practical implementation in the
form of the slide rule.
This short bibliography contains a miscellany of articles on subjects of
interest: slide rules, sectors, logarithms, mathematics, history
of science etc.
- Slide rule scales.
Lists of some of the more common scales that appear on slide rules can be
There are some goodies for you to download.
This includes a selection of cut-out and keep slide rules I've
designed, some articles and other information.
Napier invented the logarithm and published his Cannon in
1614. Have a look at a page from his
original tables or read his introduction
Interestingly John Napier invented many other aids to calculation. Perhaps the most famous of these are his bones. When laid out in the correct manner they can be
used as a set of multiplication tables.
A sector is a mathematical instrument consisting of two hinged
arms with various scales. Tell me more.
Other items of interest
The following are either items I'm hosting or external links.
If you found this interesting
[Slide rule page]
Copyright © 2002 Chris Sangwin.