Model of a Regulated Forest 473 



The drop is accomplished by a pall which engages a single 

 ratchet up to the point where the drop occurs, when the outside 

 end of the pall comes in contact with a dead shaft parallel to the 

 one bearing the pulleys. The pall is lifted out of the ratchet and 

 that pulley is free to turn back under the pull on the wire rope 

 exerted by the weight of the forest area in dropping. As the 

 handle continues to turn this pall again engages the ratchet and 

 the area again rises at the proper time. The gear wheel in each 

 half comes just to the edge of its box so that when the rwo halves 

 are unfolded the two gear wheels mesh with one another. They 

 are marked so that they are brought into contact at the proper 

 point to make the sections rise and fall in their proper order. 

 When the two halves are folded together the open ends thus 

 exposed are covered by suitable boards. These are hinged to the 

 halves and hang down under the model when not in use. 



The principal cost in the construction of such a model will be 

 first in the "trees" which at 4V2 cents per "tree" will amount 

 to about Mex. $30.00, and second, in the wages of two mechanics 

 who may require two weeks for the work. Roughly speaking the 

 total cost of both material and labor should not exceed Mex. 

 $100.00 or $50.00 gold. 



