FORESTRY EXHIBITION AT GLASGOW. 193 
and regarding this exhibit the following note, embodying the 
substance of the description which Mr Leven gave in the show- 
yard, is explanatory of the method of preservation employed :— 
The exhibit comprised stobs, etc., of Scots pine, spruce, 
beech, ash, sycamore, poplar, willow, hornbeam and oak which 
had been in use for ten years, and were still in an almost perfect 
state of preservation. The process of preservation was that 
advocated by Mr Leven in Vol. XVII. (p. 93) of the Zransactions, 
and after ten years’ experience of it, he was fully convinced of 
the efficacy, cheapness, and completeness of the system. He 
mentioned that he had a series of experiments on hand, but that 
they were not far enough advanced to warrant his explaining 
them at that time. He had, however, come to the conclusion 
that seasoning to a certain extent was advisable, and that he 
had got an open shed (a corrugated iron roof on posts) erected 
adjacent to the creosoting-tank, where the material to be treated 
could be stacked for some time. It was not essential, nor even 
advisable in the case of some woods, to season thoroughly 
before treatment, as, he said, it was a mistake to suppose that 
creosote closed up the “pores” of the timber (and this was 
borne out in a striking way by the result of an experiment 
carried out by Mr Gillanders) in the same way that paint or 
tar did. The various properties of liquids—diffusion, osmose, 
dialysis, cohesion, and probably capillarity—played parts, he 
believed, that had been overlooked in adopting certain systems 
of preservation with creosote. He, however, emphasised the 
necessity of stacking (under a roof if possible) the material after 
treatment, as the displacement went on slowly for an indefinite 
period. He also found that stobs stood driving much better 
after this treatment, and that the volatile constituents of the 
creosote were thereby rendered less volatile. A number of 
questions were asked, and in answering them Mr Leven pointed 
out that, in quantity, creosote was at that time very little over 
twopence per gallon, and that it could be had by contract for 
considerably less. 
Mr Fothringham sent from Murthly two Douglas fir stobs 
which had been in use for about eleven years, and which were 
very little the worse, an experience which tells very much in 
favour of this timber for ordinary estate purposes. The fence 
from which they were taken was partly stobbed with larch and 
partly with Douglas fir, and the ground on which it was erected 
VOL, XIX. PART I. N 
