PRACTICAL ARBORICULTURE 197 



operations, looking especially towards its future supply of cross-ties for its own 

 use, is comparatively a new idea. 



"As lo>i c twenty-four or twenty-five years ago, on the Pennsylvania lines 

 icest of Pittsburg, attention was already given to the subject, and a number of 

 catalpa trees i<. i ere planted along the right of way of one of its lines, but the results 

 obtained were unsatisfactory. 



"More recently the cultivation of the yellow locust as a tie lumber has been 

 brought to our attention, and the cultivation of this tree to a limited extent, for the 

 purposes named, has been undertaken. 



"In order to supply our entire needs for the year, namely, 3,000,000 for repair 

 and 500.000 for new work, and adding thereto 10 per cent for the immediate 

 future increase, making the total annual requirements 3,850,000 ties, we figure 

 that three ties to a tree would require about 1,300,000 trees each year to produce 

 the 3.850.000 ties (figuring that it will require thirty years for a yellow locust to 

 mature), would require a continuous growth of 39,000,000 trees, 1,300,000 to be 

 planted each year, which, if planted each year, and if planted ten feet apart, or 

 about 400 trees to the acre, would entail the continuous use of 97,500 acres, or 152 

 square miles of ground, for the purpose." 



This tree is Robinia pseudacacia, commonly called in the West black, and in 

 the East yellow locust, a valuable timber for fence posts, being durable and having 

 great density. The grain is straight and the wood is readily split into fence posts. 

 This characteristic makes it objectionable for cross-ties, as it is liable to be split in 

 driving in the spikes. The wood is so hard that it must be bored before spikes can 

 be driven. 



Four hundred trees on an acre is a far greater number than any soil in 

 Pennsylvania will support when they attain full size in thirty years, and make 

 three ties per tree, and yet the company has planted largely at six feet apart, or 

 1,210 trees per acre, seven times too many. 



In this connection we will add that the Louisville and Nashville Railway, in 

 addition to planting 150,000 Catalpa spcciosa in six separate plantations for the 

 purpose of growing cross-ties, have planted 385,000 locust trees, from which fence 

 posts will be produced. The item of fencing is one of great cost to railways. 

 To supply double lines of fence for the L. & N. system of 3,820 miles requires 

 2,444.800 posts, which must be renewed about every eight years. Thus, 350,000 

 posts will be required annually, or 500 acres of forest. 



The locust plantings are upon the rough lands in Kentucky, through which 

 a portion of the L. & N. system passes. The catalpa plantations, which are being 

 largely extended, are upon a better class of farm lands in Illinois and Kentucky, 

 and upon the sandy soils of Florida and Alabama. 



The Engineer is probably correct in his estimate of thirty years for locust to 

 mature, and during this long period other wood will have to be procured. 



His estimate of the area of land required to supply the road with 3,850,000 

 ties annually, which he places at 152 square miles, is based upon 400 trees per 

 acre. This area may be doubled, as 200 trees per acre is as many as can grow to 

 sufficient size. It will, therefore, take 304 square miles to furnish the wood. 



We place the Engineer's statement regarding catalpa in italics. 



