172 PRACTICAL ARBORICULTURE 



ering the railway tracks and filling the cuts with sand. Temporary expedients 

 have been resorted to; that of placing boards on edge, at various angles, to 

 deflect the wind and cause it to shoot the sand across the tracks. As with the 

 snow guards, this method of fences (in case of sand they are but two feet 

 high, while for snow they are five feet high) is quite expensive, and requires 

 frequent removals as the sand fills about the board. 



It occurred to the company to plant the common willow, which grows 

 along the shore, in lines along the track, for the purpose of catching and re- 

 taining the sand. 



With snow, an accumulation made in winter melts and disappears the 

 coming season. Not so with sand, but it remains where it is deposited, in- 

 creasing in depth, until removed by the wind or with the steam shovel. 



This is an arid country and few trees will thrive, and the plant which will 

 perform the service required must be of rapid growth, able to withstand the 

 overflowing of the stream and the subsequent dryness which follows the reces- 

 sion of the waters. Willows of many varieties will fulfill the first condition, 

 but only a few will survive the dry seasons which follow. Probably the 

 Golden willow would be better suited for the purpose. This is Sali.r alba, 

 var., which thrives under both moist and dry conditions. It makes a high 

 tree, and would, therefore, be far superior to the bushy growths along the 

 Columbia. The Golden willow grows readily from cuttings, although for this 

 location they would have to be rooted in a nursery, or bed, where moisture 

 abounds, after which they would grow in this sand. As the sand is deposited 

 by the wind, slowly covering the bushes, the tree will continue its upward 

 growth, keeping above the surface, continually forming new roots as the 

 sand rises about the trunk. There are instances where shifting sands have 

 buried a willow gradually until thirty feet of the trunk was beneath the sur- 

 face, yet the green branches and leaves extend above the sand. 



When once a barrier of sand has been formed along the bank of the river, 

 and the surface covered ivith verdure of living trees, the sand motion will cease. 



There are many places where this problem of checking the sand move- 

 ment confronts a large community ; that at San Francisco, at Golden Gate 

 Park, being prominent. Cape Cod, Mass., and Michigan City, Ind., are other 

 instances. The folly of scattering pine and other seeds of slow-growing trees 

 has been fully demonstrated. Before the seed can germinate and establish a 

 root system, a majority will have been covered deeply with sand. 



About the south end of Lake Michigan, in Illinois and Indiana, are sand 

 hills which were but a few years ago covered with oak and maple trees. These 

 hiils were, in centuries past, formed by the wind blowing the sand from the 

 lake shore. Gradually they became covered with trees through natural meth- 

 ods, and the shifting of the sands was checked. 



Certainly this occupied much time, as nature is deliberate in all her works. 



It is sheerest folly and a waste of time and labor to scatter seeds of any 

 kind upon these moving sands, as they may be covered deeply long before 

 they have time to germinate. But after securing a stable surface by such 

 plants as yucca, beach grasses, and trees which grow quickly, then pine and 

 more important tree growths may be secured. 



