Frank Cousins popularised the scales made by E. C. Middleton which were
based on Samuel Foster's work in 1638, made practical by George Serle in

This is a PDF file of around 250k, four pages, and has a very simple explanation of how to use the
Middleton Scales for horizontal, non declining vertical, and declining vertical dials. Includes a scale,
the formulae for the scale, and values for time and latitude. The scale can also be used with polar
and meridian dials.

general spreadsheet

Here is a one page PDF file of the scales, you print the page, cut it out, and fold it. Has the scales on
the front, and an EOT, Julian day, and Declination table on the back.   Low resolution version, see to
the right.

Frank Cousins in his book discusses their proof and usage for declining dials.
The main web page
has a link to Abebooks into a search engine for Cousin's book ~ usually several are available

A search on the internet on MIDDLETON SCALES will often get
a web site discussing them, and if in
a foreign language, a translate option is available from the search engine.

The North American Sundial Society has additional material for this method, including Middleton's
original typed notes which also show the scales being used for polar (equinoctial) dials as well as
east and west facing meridian dials. This is on the optional CD.