USE OF EXPLOSIVES AND THE BLOW-I.AMP IN THE GARDEN, 7 



ON THE USE OF EXPLOSIVES AND OF THE BLOW-LAMP 

 IN THE GARDEN. 



By Herbert E. Durham, ScD., M.B., B.C., F.R.C.S, 



[Read Feb. 24, 1914; Sir Albert K. Rollit, LL.D., in the Chair.] 



Explosives. 



After having been somewhat concerned in trials of explosives for 

 agricultural purposes on the large scale, through my friend Mr. Harold 

 Barnett, the pioneer in Herefordshire (in November 1912), the 

 thought came to me, why not try these agents on a small scale on 

 my garden ? And the thought became more fixed from the cir- 

 cumstance that, though my garden has been under cultivation for 

 some fifty or sixty years, the surface has apparently never been dug 

 more than two spits deep ; moreover, the amount of labour and time 

 needed to trench a patch three full spits deep was considerable — of 

 the former because the subsoil consists of a stiffish clay containing 

 large stones, which necessitated the use of the fork before it could 

 be turned with the spade, and of the latter because, through weather 

 conditions, some two months elapsed ere a piece ten by eighteen yards 

 in extent could be completed. 



I do not propose to detail the history of the procedure, which 

 was, I believe, first used in the United States of America for sub- 

 soiling, ditch-making and tree-planting. The blowing up of tree 

 stumps is a comparatively old and well-known use for explosives. 



It may be objected that my own experiments are on too smaU 

 a scale and too recently instituted for making generalizations at the 

 present time ; still the record of the first season's results may be of 

 sufficient interest to justify their publication. 



The leading idea in their use is, of course, to crack and fissure 

 the subsoil so as to allow air to enter, and water to percolate, especially 

 where, from the eifects of weather and cultivation, an impervious 

 layer of clay or silt, known as a pan or hard pan. has been developed ; 

 that is to say, to promote the aeration and drainage of the sub- 

 soil, more deeply and with less expenditure of labour and time 

 than is feasible with the spade. It has also been suggested that 

 the nitrous fumes might have some manurial value of themselves 

 and cause some destruction of soil pests. With regard to the latter, 

 I may note here that some Witloof Chicory roots which had been 

 heeled in right over the site of subsequent explosions, were found 

 to be infested with live slugs a fortnight later ; the fumes from the 

 explosive had been seen issuing from amongst the roots, so that, so 

 far as concerns slugs, no effect was produced. 



For quick preparation of the ground for tree-planting, the use 



