Britten F.J. The Watch, Clock Makers Handbook. Dictionary and Guide

9th ed. — London; New York: Spon and Chamberlain, 1896. — 460 p.In the following pages I have endeavoured to define the various technical terms used in watch and clock making, and have added such information as I possessed that seemed likely to be useful to young workmen and students.For the French equivalents I am indebted to Mr. Mairet, and for the German to Mr. Immisch.The whole of the Fourth Edition of the “Watch and Clockmakers’ Handbook,” as well as much new matter, appears here under headings arranged alphabetically, except the Lengths of Pendulums, and other tables required for constant reference, which now form an Appendix.I have to acknowledge the kindness of the Council of the Horological Institute, who generously placed the blocks in the “Horological Journal” at my disposal, and of many other friends who have given me valuable assistance.French and German equivalents, printed in italics, refer to the first definition in cases where the title has more than one meaning.Alarum. [Réveil. — Der Wecker.] - Mechanism attached to a clock by which at any desired time a hammer strikes rapidly on a bell for several seconds. Generally, a separate weight or spring actuates an escape wheel, to the pallet staffof which a hammer is fixed to act on the inside edge of a hemispherical bell. The alarum is usually let off by a wire attached to the hour wheel a that stops the escape wheel. (See also " Striking Work.") In the "Speedwell" alaruin the same mainspring serves for the going train and the alarum as well. The great wheels of the going and alarum trains are mounted on the winding arbor, one on each side of the mainspring. The wheels are loose, and driven ratchets and clicks to allow of the arbor being reversed