» 



February, 1912.] 



turn to the former, it is expedient, in 

 this place, to indicate the functious of 

 the chief publications issued by this 

 Department. In these an attempt is 

 made to attain, at least in some degree, 

 the specialization which is requested in 

 the publication named at the commence- 

 ment of this article. This present 

 journal, the Agricultural News, has for 

 its particular object, to state it shortly 

 that which is epitomized in the expres- 

 sion, Extension Work ; while the West 

 Indian Bulletin purports to deal with 

 matters of more precise scientific or 

 administrative interest. In another 

 direction, the Annual Reports of the 

 several Botanic and Experiment Sta- 

 tions are confined to sta cements of the 

 work accomplished during the periods 

 under review ; there is little attempt in 

 these to undertake the function that has 

 been termed Extension. 



In view of the general considerations 

 above; it should be evident that, as the 

 work of agricultural investigation must 

 derive its scope from its particular ob- 

 ject; in the same way, it is expedient 

 that those who issue agricultural publi- 

 cations should make their contents con- 

 sistent with their purpose. If these 

 matters are kept well in mind on the 

 part of the workers in connexion with 

 agricultural investigation, much of the 

 misunderstanding that is evidenced 

 from time to time by those for whom 

 they work will cease to exist and there 

 will be a corresponding increase of sym- 

 pathy between the adviser and the 

 advised. 



STUMP-CLEARING BY EXPLOSIVES. 



(From Tropical Life, Vol. VII., No. 12, 

 December, 1911.) 



Many, perhaps most, people only asso- 

 ciate explosives with war, mining, rock- 

 blasting, and occasional anarchist out- 

 rages ; f cr a good many years, however, 

 high-class explosives have been used with 

 great success for clearing forest and 

 other land of trees, stumps, boulder, 

 rabbit warrens, ant-hills, &c, and on 

 this account should specially appeal to 

 those clearing land in the Tropics. In 

 freshly opened areas it has the great 

 advantage of breaking up the soil and so 

 rendering it more easy to cultivate ; on 

 some hard soils its use can alone make 

 it possible to secure profitable crops. 

 Thanks to modern improvements in the 

 blasting cartridges and the introduction 

 of electric detonators for exploding the 

 charge, this can be done without risk, 

 and at very little expense and trouble. 

 When removing the largest trees and 



21 



161 Miscellaneous^ 



stumps, after the necessary boring has 

 been done, two or three holes only being 

 required, the operation takes only a few 

 minutes. The size of the tree is of no 

 apparent consequence, it is only a matter 

 of a hole more or les9, a larger cartridge, 

 or a stronger explosive ; in other respects 

 the methods employed and the labour 

 involved are just the same. As regards 

 the boring, this can be done in two 

 ways : — 



No. 1.— By boring into the earth imme- 

 diately under the tree or stump. 



No. 2.— By boring through the large 

 roots of the tree or stump. 



The first method is called an earth- 

 hole, and this is the best method where- 

 ever practicable, the boreholes being 

 rapidly prepared with very little labour, 

 and the concentration of the charges of 

 explosives well under the tree or stump 

 will ensure success. 



The second method is to bore the 

 hole or holes in the spur or large roots 

 of the tree or stump, sufficiently deep 

 to burst the wood. By this process the 

 charge, when fired, shatters the large 

 roots and completely severs them from 

 the trunk, whilst the united force from 

 the concerted action of the various 

 charges causes the tree or stump to be 

 completely uprooted. 



In preparing a borehole of the first or 



earth-hole" description, the following 

 instructions should be observed : - 



Locate any possible opening between 

 the roots for starting a borehole, taking 

 care not to disturb the surrounding 

 earth. 



When an opening has been found, 

 boring operations may commence, and 

 for this purpose a crowbar or a 3 in. earth 

 auger may be used — the latter for pre- 

 ference—and the hole bored under the 

 tree or stump in a slanting direction 

 towards the centre tap-root, or centre 

 of the tree, using a little water to facili- 

 tate boring operations. 



The operator must be guided by cir- 

 cumstances as to where holes should be 

 bored, but a safe method to adopt is to 

 locate the boreholes in such a way that 

 all point to one common centre, viz., the 

 heart of the tree or, assuming the tree 

 or stump to require three holes for 

 blasting purposes, let the boreholes be 

 so divided that each hole is carrying 

 about one-third of the burden of the 

 tree ; in this way the tree or stump is 

 balanced, so to speak, upon the three 

 holes. If this system is adopted, good 

 results will follow if the timber is sound. 

 Should the tree be hollow, however, 

 the holes should be carried under the 



