486 SEC. 12. APPLIED MECHANICS. 



2143c. Drawing of the Machine. F. Engel, Hamburg. 



2144. Bevel-Wheel Gearing. 



Royal Geological Institute and Mining Academy (Director , 

 Prof. Hauchecorne), Berlin. 



The models exhibited are a small portion of the collection used for 

 machine-instruction in the Kb'niglicheii Berg-Akademie (Royal School of 

 Mines). They have been made specially for this purpose by Herr Maiss, in 

 the workshops of the Academy, upon the designs of Prof. Hermann. The 

 models of separate mechanisms have been constructed upon the principles 

 laid down in Prof. Reuleaux's " Theoretische Kinematik " ; they are all 

 arranged for " inversion," that is, so that either of their links may be fixed in 

 the screw stand exhibited with them, and the various properties and applica- 

 tions of the inversions easily shown. 



The models are all made with the special view of illustrating in the most 

 complete, clear, and simple manner the principles of the machines and 

 mechanisms which they represent. All details not required in this relation 

 are omitted or made subordinate, the parts which it is important for the 

 students to observe are polished, the other parts, in order not to attract 

 attention unnecessarily, are made a dead black, so that all disturbing 

 reflections of the light are prevented. Care has been taken also to arrange 

 them so that all essential parts and their combinations may be visible at a 

 glance in all parts of the class-room, so that the alterations which it is 

 necessary to make during the lectures may occupy a minimum of time, and 

 altogether that teachers may find their use in demonstrations very convenient. 

 In the steam-engine models have been made, the relative dimensions and 

 arrangements, as far as possible, to resemble those of actual practice. 



2144a. Pair of Worm- Wheels, with parallel axes. 



Royal Geological Institute and Mining Academy (Director -, 

 Prof. Hauchecorne), Berlin. 



2144b. Worm- Wheel, with inclined teeth. 



Royal Geological Institute and Mining Academy (Director, 

 Prof. Hauchecorne), Berlin. 



2144c. Annular Wheel and Pinion. 



Royal Geological Institute and Mining Academy (Director, 

 Prof. Hauchecoi*ne\ Berlin. 



2144d. Hypocycloidal Gearing. 



Royal Geological Institute and Mining Academy (Director, 

 Prof. Hauchecorne), Berlin. 



2144e. Worm-Wheel, with straight teeth. 



Royal Geological Institute and Mining Academy (Director, 

 Prof. Hauchecorne), Berlin. 



2144f. Pair of Worm- Wheels, with axes at right angles. 

 Royal Geological Institute and Mining Academy (Director, 

 Prof. Hauchecorne), Berlin. 



