o£ the VyhanonieteTi 401 



ii a Roman balance to weigh burdens. In fhort, nothing 

 would be more eaiy than to convert t into an anemometer, 

 to difcoyer the abfolute force of the wind, by fitting to it a 

 frame of a determined fize filled up with wax-cloth ; and 

 it would not be impoffible to afcertain by this machine the 

 recod of fire-arms, and confequently the ilrength of gun- 

 powder. 



This dynanometer, in its form and fize, has a near refem- 

 blance to a common graphometer. It confilts of a fpring 

 twelve inches in length, bent into the form of an ellipfisj 

 from the middle of which arifes a femicircular piece of brafs, 

 having engraved upon it the different degrees that exprefs 

 the force of the power acting on the fpring. The whole of 

 this machine, which weighs only two pounds and a half, op- 

 pdfes, however, more refinance than may be neceifarvto de- 

 termine the action of the ftrongeft and molt robutt hoiie. 

 The fimplicitv of its mechanifm will be better illuftrated by 

 the following description : 



A, an elliptical fpring) fecn in perfpeclive, covered with 

 leather, that it may not hurt the fingeis when firongly preffed 

 on with the hands, [fee Plate XIII.) This fpring is com- 

 pofed of the beft ftcel well welded and tempered, and after- 

 wards fubjecled to a ftronger proof than is indicated by its 

 graduation, in order that it may not lofe any of its elafticity 

 by ufe. 



B, a piece of fteel ftrongh" fattened to the fpring by means 

 of a claw and fcrews, in order to fupport a femicircular 

 plate of brafs C, mounted on the fpring, feen geometrically. 

 On this plate are engraved two arcs, one divided into my- 

 riagrarrimes, and the other into kylogrammes. Each of thefe 

 arcs is (till farther divided by points, which exprefs the 

 weight in pounds de marc, and all thefe degrees having 

 ljeen exactly valued by accurate weights, it thence refults 

 that all dynanomet'ers of this kind may be compared with 

 each other. 



Vol. I. D d B, a 



