Keelhoff, F. <br/><br/>
Theory of terminal curves for the hairspring / F. Keelhoff ; translated by G. Droz and William O. Bennett. 

 - 20, 5 pages ;  27 cm 
<br/><br/> English translation of a portion of the original French work: Théorie des courbes terminales du spiral. Brussels : Académie Royal de Belgique, 1921. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Balance springs.<br/>Spirals.<br/>Clocks and watches--Design and construction.
<br/><br/><label>Subjects--Index Terms: </label>Watch (general) Not Geographic hairspring termina curve unpublished manuscript watch balancewheel advanced theory TheoryGeneral Keelhoff, Fr.