Charles Frodsham, and his son Harrison Mill Frodsham were both erudite writers on numerous aspects of horology. They published articles, discourses, pamphlets and tables in theoretical and practical subject matters as well as taking out a number of horological patents. Some of these are listed below.
On the Laws of Isochronism of the Balance Spring as connected with the higher order of Adjustments of Watches & Chronometers
In 1846, Charles was made an associate member of the Institution of Civil Engineers. A condition of membership was to read a paper before the Institution. The lecture was delivered on 27 April 1847 and the 33-page paper was published in 1849 along with an abstract of the discussion upon the paper, consisting of remarks by Mr Vulliamy and Mr Farey with replies from Charles Frodsham. The pamphlet was later reproduced in a Charles Frodsham catalogue of Chronometers and Fine Watches in 1898.
Contents: The subject proposed – Useful to watchmakers – The most necessary part of a good watch – Example of a non-isochronal spring – Its proper remedy – Improvements in horology originated by Dr. Hooke – Introduction of the balance spring – Hooke’s knowledge of its isochronism – Not understood by Harrison – Controversy regarding, by French artists – An experiment by Berthoud – The difficulties of early watchmakers – Isochronism an inherent principle of the balance spring – Reasons for, and explanation of – Five conditions of isochronous vibrations – Material of balance spring – Elasticity of, to be aimed at – How moderated – Two forms of spring – Modes of proving and of correcting isochronism – Various examples of error to be corrected – An account of spiral springs – The nicety of their operations – Difference of isochronism in watches and chronometers – The advantages of isochronous springs – The mode of attaining perfection in isochronism – Conclusion.
The Universal Standard of Time throughout Great Britain
This booklet published in 1848 was Charles’s reply to an article printed in Blackwood’s Magazine regarding the introduction of Greenwich Mean Time. At the time the general public were not disposed to the surrender of local time for Greenwich Time. This booklet was written in favour of its adoption.
A Few Remarks upon the Construction and Principles of Action of the Aneroid Barometer
30-page booklet published in 1849.
Improvements in Watches based on Experience with the Chronometer
Special pamphlet published circa 1852 in Spanish. No copies are known to be extant, although an English translation was made. This pamphlet discusses, in the form of an advertisement, Charles’ new watches and their suitability for general use in Spain and the Americas.
A Set of Five Tables for Facilitating the Operation of Timing watches and Chronometers and A Table Showing the Diameter and weight of Balance Suited to Different Kinds of watches and Chronometers
Both published in 1853.
Description of Charles Frodsham’s Register, or Split Centre Second’s-Hand Watch and Companion to Charles Frodsham’s Register
A pamphlet and accompanying sheet discussing the use of the watch which was accurate to a quarter of a second.
On Mainspring Adjusting Rods
6-page pamphlet published in 1855. Contents: for the adjustment of the mainsprings of chronometers and watches, and for ascertaining their relative strengths in ounces and penny-weights troy, in connection with his law of the balance as to weight and diameter.
A Few Words to do Justice to English Chronometer, Watch, and Clock Making
A series of letters and articles published in the Horological Journal, July-October 1860, concerning wheel trains and compensation balances. Included is Charles Frodsham’s General Table of Trains, from 240 to 400 vibrations per minute.
A Few Facts Connected with the Elements of Watch and Clock Making
41-page booklet published in 1862. Contents: On the advantages of a new nomenclature and measurement for all parts of English watches, clocks, and chronometers – Description of gauges introduced – Account of the universal adjusting rod, a tool for showing the power of mainspring due to a certain cubic space in the barrel – The best dimensions of watches and chronometers recommended for the pocket; together with many useful tables, which every watchmaker ought to know. Subjects covered include; the vernier slide gauge, the universal adjusting rod, the Duo-in-Uno balance spring, the slide rule, the Lancashire gauge, the Lancashire pillar gauge, the Frodsham movement gauge, the Frodsham pillar gauge, general principles of gearing, lengths of pendulums in London, weights and measures (including foreign), dilation of different substances by heat, specific gravities, and fusing points, solders and boiling points of various metals.
Mercurial Compensation pendulums, their Construction and Adjustment
9-page booklet published in 1866. Contents: New brass tubular pendulum with mercurial compensation, for astronomical and other regulators. A discourse on the advantages of brass over steel rods, and tubes for the construction of mercury pendulums with calculations for regulating.
A Short History of The Marine Chronometer and The Laws of the Isochronism of the Balance Spring
40-page booklet published in 1871. The Laws of… Reproduced from the 1847 lecture, and the subsequent 1849 publication. Contents of A Short History… : The two chief instruments used in navigation – The earliest modes of marking time – The true beginnings of horology – The turret clocks of the eleventh century – The first watches – Their ill reputation – The first scientific notation of time – Galileo – The isochronism of the pendulum – The statement of the great want of the mariner – Public rewards offered for a timekeeper – The efforts of Christian Huygens and of Dr. Robert Hooke – The substitution of the balance spring for the pendulum – The isochronism of the balance spring – A galaxy of eminent mechanicians – The first marine chronometer – The rapid improvements on it – The Arnold Earnshaw compensation balance – Trials of chronometers at Greenwich – Perfection of existing marine chronometers – the triumph of human ingenuity.
16-page booklet published circa 1878, and enlarged from the Horological Journal, June 1878
Contents: A description, by permission, of the Sympathetic clock and watch, the property of her Majesty The Queen. With 2 photographs and escapement drawings.
Some Materials for a Résumé of Remontoires
An in-depth and well illustrated series of eleven articles written by Harrison Mill Frodsham for The Horological Journal, Oct 1877, Dec 1877, Jan 1878, Feb 1878, Mar 1878, Apr 1878, May 1878, Jun 1878, Aug 1878, Jan 1879, and Feb 1879, covering his study of remontoire escapements, including a classification and descriptions of remontoires invented by other makers and patentees.
Frodsham’s Trochilic Escapement
A description of the Trochilic spring detent escapement for: The Horological Journal, Nov 1885. Explains this ingenious method used to lessen the danger of tripping (un-locking at the wrong time) in a spring detent escapement.