| http://www.w3.org/ns/prov#value | - 'Ihe invention will be more readily understood irom a reading of the following specification angl by reference to the accompanying drawings, in which an example of the invention is shown, and wherein: Figure 1 is a transverse, vertical, sectional view of the lower portion oi the bore hole which requires cleaning, Figures 2 to 5 are similar views, illustrating the various steps of the improved meth
|
