XI. MODELS, ETC. 469 



2298. Model of Link Motion in a Wool Combing Ma- 

 chine. 



2299. Model of a Ventilating Fan. 



2300. Model of Knuckle Joint. 



2301. Knuckle Joint, with crank and connecting rod. 



2302. Model of Stanhope Levers. 



2303. Model of Lever Shears. 



2304. Circular into Reciprocating Motion, with four beats 

 for each rotation. 



2305. Circular into Reciprocating Motion, with alternate 

 intervals of rest. 



2306. Model of Screw Surface. 



2307. Model to show Difference of Inclination in 

 Screw Threads of the same pitch, traced on cylinders of different 

 diameters. 



2308. Model of Endless Screw and Worm Wheel. 



2309. Rolling Contact between Hyperboloids, with gene- 

 rating line mounted separately. 



2310. Model of Skew Bevels. 



2311. Two Axes, connected by a cord and grooved pulleys. 



2312. Chain and Pulley. 



2313. Pantograph, for drawing similar curves. 



2314. Model of Watt's Parallel Motion. 



2315. Model to illustrate the principle of Watt's 

 Parallel Motion. 



2316. Outline Model of Beam Engine, with Watt's parallel 

 motion. 



2317. Model of Roberts' Parallel Motion. 



2318. Model of Peaucellier's Straight-line Motion. 



2319. Sectional Model of a Trunk Engine. 



2320. Model showing Expansion Valve. 



