REMONTOIR. 



The wheel now adv.Tnces a little way, jufl; enoiipjh to allow 

 the iiiterior end of the levcr-pallct to pafs back, again, as 

 urged by the fpiral fpring, wiiile the remote end of the 

 faid lever gives an impulfe to the balance, through the 

 pallet D ; the tooth 4 is then locked on the concave 

 fide of the locking claw b, and the interior end of the 

 lever-pallet partly fupi)Orts tlie following tooth ; in this 

 fituation the ofcillalion is finiflicd, and on the return of the 

 balance pallet E, ilriking the prong of the fork in a con- 

 trary direftion, as^ain unlocks the wlieel from claw b, while 

 the force of this wheel is partly fufpended by the end of 

 the lever-pallet ; being now at liberty, the wheel proceeds to 

 wind up the remoiitoir-fpring again, till another tooth falls 

 on the claw a, now brought inwards, when the operation 

 is completed, and the preflure of the inner end of the lever 

 pallet againll its contiguous tooth again relieve;: the claw a 

 from a part of the prcll'ure of the wheel, and thereby ren- 

 ders the unlocking as eafy as before, when claw b was un- 

 locked. This cfcapement appears to us an improvement 

 on Haley's, both as to its fimplicity and fafety of locking, 

 and the inventor propofes a (till further fimplilication, by 

 fubllitutuig a ilraight remontoir-fpring for the fpiral one, 

 particularly in time-pieces intended to remain in a llationary 

 fituation, where the weight of the fpring would form no 

 objeftion ; but it does not appear that iuch conllruftion 

 was ever adopted. The fimplicity of the locking of the 

 remontoir-fpring by the wheel itfelf, where this fpring and 

 the maintaining power mutually re-aifl, requires, as might 

 be forefeen, an unufually llrong maintaining power, which 

 is, perhaps, one of the greatell objeftions to this mode of 

 applying the remontoir ; unlcfs, indeed, what was remarked 

 by the fociety's committee be true, that the balance mull 

 vibrate in a large arc before the piece will continue to per- 

 form. 



MaJfey'L—lih-. Edward Mafley, of Hanley, in StafFord- 

 fhire, received a reward of fifty guineas from the Adelphi 

 Society, in the J'ear 1803, for his invention of two dif- 

 ferent clock efcapements, one of Avhich we have already 

 defcribed, under our article Escapement, as being with- 

 out a verge ; and the other we (hall make the fubjeft of 

 our prefent feftion. Fig. j. of Plate XLII. reprefents fo 

 much of Mafley's remontoir efcapement as is fufficient to 

 explain all the ellential parts ; in which A is the fwing- 

 ■wheel ; B, C, are two detached pallets, moving on feparate 

 arbors, at oppofite fides of the fwing-vvheel ; B is feen 

 urged by the remontoir-fpring E, by the aid of a tail-piece 

 fixed on the arbor of pallet B, which receives the aftion ; 

 and the other pallet muft be conceived to have a fimilar 

 fpring and tail-piece, which cannot eafily be reprefented in 

 the drawing ; F is the verge bearing two arms without 

 pallets, which prefs under the pins of the detached pallets, 

 and raife them alternately, at each vibration of the pen- 

 dulum, from the teeth of the fwing-wheel, which had been 

 previoufly impelled by the maintaining power, and K is 

 the pendulum fufpendcd in the ufual way, and having a 

 crutch to communicate its force to the verge at the mo- 

 ment of withdrawing the pallets. All, therefore, that 

 the pendulum has to do, is, to difengage the pallets from 

 the teeth of the fwing-wheel that locks againft the in- 

 clined planes of the pallets ; for the remontoir-fpring then 

 oppofes the afcent of the pendulum, and aids its defcent, 

 by means of the connection between the pins of the pallets 

 and the arms of the verge, which muft, from the nature 

 of the conftruftion, continue in contaft during a large 

 portion of each cxcurfion of the pendulum. It is not 

 ftated in the author's account (Tranf. Adel. Soc. vol. xxi.) 

 at? what part of the arc of vibration the pendulum unlocks 



either of the pallets, but it feems to us capable of being 

 made to effeft this office at its point of greatijl ndocUy, if 

 it does not do that as now confirufted. An attention to 

 this particular is of the utmoil importance in any cfcape- 

 ment, fince the natural law of gravity is tlie leaft deranged, 

 when any force is given, or taken away, when the pen- 

 dulum is at the loiuejl point of its arc, for the velocity it 

 has at that point determines the height to wiiich the ball 

 fliall rife ; but any addition or diminution of the pendulum's 

 momentum, beginning at any other point of the arc, either 

 adds to, or diminiflies the natural length of the vibration, 

 and injures the ifochronifm. Befides, a fpring commencing 

 both its accelerating and retarding influence at the point of 

 the pendulum's greatefl velocity, afls, not only by a law 

 commenfurate with the law of gravity, but their various 

 forces, thus exerted, are contemporary, and, therefore, aft 

 together as one ; a confidcration which never fhould be lolt 

 fight of in the conftruftion of an efcapement of anv de- 

 nomination. The principal advantages that the author 

 leems to iiifift on in this elcapcment, are, that the friftion 

 is diminiflied at the afting parts of the pallets, the impulfe 

 bi-iiig given by a direft pi]fl}, without, or with very little. 

 Hilling motion ; and that a certain regular momentum is 

 kept up in the pendulum, independently of any variation 

 which may occur in the wheel-work, or in the adting part 

 of the pallets during the fliort lime of unlocking ; but, 

 what is the principal objeft of fuch a contrivance, he has 

 not ftated, perhaps not coiifidered, how this certain tegular 

 momtntum is, or ought to be, modijied. — Indeed, in fpeak- 

 ing of his other efcapement without arbors, he fays, that 

 one of its advantages over this is, that during z. part of the 

 vib-ation the pendulum i-s difengage d ; from which remark, 

 it fhould feem, that he thinks the conilant aftion of this 

 remontoir-fpring, however modified, an objeftion to be 

 avoided. 



Antis^. — In vol. xxiii. of the Tranfaftions of the Society 

 laft mentioned, it is Hated, that Mr. John Antis of Fulneck, 

 near Leeds, fent this focicty a model of a new clock efcape- 

 ment in 1805, with a correfponding defcription, for which 

 a reward was voted him of twenty guineas. The model is 

 depofited in the room at the Adelphi appropriated for 

 the reception of models, but as the defcription is not pub- 

 liflied in the Tranfaftions of the Society, nor an engraving 

 given of the model, we muft infer, that the contrivance 

 either is not new, or is not of fuch importance as to merit 

 the particular notice that has been given by them to the in- 

 ventors of like contrivances, who both preceded and fol- 

 lowed him. Indeed, in the letters of Mr. Antis to the 

 Society, publilhed with their account of the rewards, it 

 feems that two efcapements were fent them, one a detached 

 one, and the other, one that " would equalife the power of 

 the impulfe," which muft, therefore, have been of the 

 remontoir defcription ; but he confefles that thefe contrivances 

 by him " may have been praftifcd before." With refpeft 

 to the latter efcapement, he remarks, what is worthy of 

 being recollefted by clock-makers in general, that, by its 

 means " a fpring-clock will be as perfeft as one which goes 

 by weight, and more fo if tihe latter has no remontoir." 

 Should any of our readers have a wifh to fee and examine 

 Mr. Antis' produftions, which, he acknowledges, are done 

 in a rough manner, and under difadvantageous circumftances, 

 but which may not be the lefs ingenious on that account, 

 there will be no difficulty in gaining adniiffion to the model 

 room, where the original work is preferved with a view to 

 public infpeftion, provided the applicant be properly iu" 

 troduced. 



Mendham'f,—lt frequently happens that confiderable 

 4Q a improve- 



