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68 FORESTS, WOODS, AND TREES 
of these being 18 to 24 feet high in 1912. Oak, ash, 
beech, sycamore, and elm also did fairly well. This is 
remarkable, considering the character of the mound, of 
which only the surface has disintegrated, the material be- 
neath being caked into hard masses containing considerable 
quantities of pyrites. In spite of this, the trees have made 
nearly as good growth on the mound as trees of the same 
species in ordinary soil in the neighbourhood, according to 
measurements made by Mr. P. Murray Thomson (5). 
In the colliery districts of Scotland a few attempts have 
been made to plant the spoil heaps, which are locally known 
as pit bings (6). When these consist of a mixture of shale 
and stones, trees grow readily, the best species being prob- 
ably alder. Successful results have been obtained by Mr. 
Whitelaw at Gartshore, near Kirkintilloch. Mr. J. Milne 
Home sends me some notes about recent plantations on pit 
banks near Dalkeith. On the upper bing on Wester Cowden 
Incline, which was an old colliery pit bank that had been 
left untouched for many years, an acre was planted in 1913 
with 1200 sycamore, 450 birch, 2000 grey alder, and 
1200 European larch. At present grey alder shows the 
best growth, while larch has done fairly well, but sycamore 
has been a failure. In 1914 about 24 acres on the neighbour- 
ing lower bing were planted with 2300 sycamore, 500 birch, 
and 4200 grey alder. It will be interesting to watch the 
further growth of these two plantations. Before the war 
grey alder was procurable at a cheap rate from French 
nurseries aS one-year and two-year seedlings. It grows 
with great vigour on most soils, and succeeds in wind- 
swept localities and in situations lable to late and early 
frosts. Its wood is equal in value to that of the common 
alder. 
Mr. H. M. Cadell (7) tells me that about ten years ago 
he planted up some old colliery bings at Grange, Linlithgow, 
with Japanese larch, Scots pine, etc. The Japanese larch 
are now about 15 feet high, but a good many have died. 
These pit heaps, though forty years old, were not suffi- 
ciently disintegrated, and the dry undecomposed material 
b 5 6 25--¢ Seeger 
