156 



AMERICAN FORESTRY 



RAILROAD CURVES AND T-SQUARES 



T-squares are often of mahogany and cherry, ot of black or Cir- 

 cassian walnut, though other woods which season nicely may be 

 used. The railroad curves shown in the picture are made 

 of pear wood. Experience has shown this to be an excellent 

 wood for this instrument and it is preferred before most others. 



because a few fine woods are made into rather cheap 

 articles, and some woods which are common enough may 

 form parts of fine instruments. 



Seven of 

 these woods 

 are foreign, 

 the others na- 

 t i V e of the 

 United States. 

 The fore i gn 

 woods and the 

 principal 

 countries o f 

 origin are here 

 given : 



West Indies, 

 boxwood 

 (T a b e u i a 

 pentaphylla) is 

 hard, strong, 

 of a yellow col- 

 or, and has a 

 fine, smooth 

 grain. The 

 wood is ob- 

 tained in the 

 West Indies, 

 Panama, Bra- 

 zil and adja- 

 cent regions. It 

 is Vnown under 

 various names 

 in different 

 countries, 

 amnnc: such 

 l)eing 7.a])atero, 

 white cedar, 

 rngwood and 

 whitewood. It 



WOODEN TRIPODS 



The tripod is in general use for mounting scientific instruments which require a firm base 

 and need to be moved frequently from place to place. The illustration herewith shows a 

 telescope on its tripod, and another style of mounting is shown, such as commonly forms 

 part of the surveyor's transit. Maple is most used for this purpose. 



SMALL WOODEN GAUGES 



A class of gauges which are alike in their main features but dif- 

 ferent in minor particulars and details. The finest are of box- 

 wood or ebony, but the common sorts are quite satisfactory if of 

 beech, hickory, maple, hornbeam or mahogany. 



is nearly as 

 hard as Turk- 

 ish b o X w ood 

 and one of the 

 most accept- 

 able substitutes 

 for it for many 

 purposes. It is 

 liable to split 

 open during 

 the process of 

 seasoning, and 

 for that reason 

 it is difficult to 

 season. This 

 tree seldom de- 

 velopes heart- 

 wood that is 

 distinguishable 

 from the sap 

 by its color. 

 The largest use 

 is in the manu- 

 facture of fine 

 rulers. It does 

 not go much 

 into cheap ar- 

 ticles where 

 less valuable 

 woods will 

 answer. It is 

 p a r t i c ularly 

 valuable for 

 rulers because 

 i t s hardness 

 and fine grain 



