310 



The " Buckeye " Ditcher. 



[July, 



Arrangements should be made to lay the pipes close behind 

 the machine, as delay in doing this will probably result in 

 loose earth falling into the finished excavations. 



Conditions Encountered.— The soil at Croxton is a stiff 

 boulder clay of considerable thickness which, as explored to a 

 depth of 4 ft. 6 in. by the excavator, contained a few large 

 boulders and bands of chalk pebbles mixed with gravel. In 

 places, however, uniform sticky clay was found to the full 

 depth of the drains. 



Fields of two types were attempted: — The demonstration 

 field was a 12-acre bare-fallow of gentle and fairly uniform 

 slope. There was about 5 in. of dry friable soil on the surface, 

 but below the clay was moist and sticky owing to the con- 

 servation of water by the fallowing operations. In the upper 

 parts of the field, bands of chalky gravel were found in the 

 clay. The other set of conditions encountered consisted of 

 wheat stubbles; these presented hard-baked clay surfaces 

 resting on dry clay of a type containing rather more chalk and 

 gravel than in the wetter parts of the demonstration field: the 

 comparative dryness of the subsoil here was no doubt due to 

 the absorption of water by the roots of the wheat crop. 



The mechanical analyses given in Table I show the 

 nature of the various fields just described. Since the bulk of 

 the earth excavated by the machine consisted of subsoil, the 

 analytical figures for the respective subsoils probably give a 



Table I, showing percentages of Constituents. 



Soil number. | 



Stones. 



Moisture. 



Organic Matter. 



Fine Gravel. 



Coarse Sand. 



Fine Sand. 



Coarsfe Silt. 



Fine Silt. 



>. 



OB 



O 



Chalk. 



Total percentage of water 

 at time of excavating. 



Area represented 

 by sample. 



1 



7 



2-0 



6-8 



5 



8-6 



17-9 



7-5 



14-2 



32-0 



7-4 



j 14-2 ! 



Surface of the stiffer 

 and wetter parts of 

 demonstration field. 



2 



•4 



2-4 



8-0 



M 



5-7 



12-2 



9-5 



9-3 



35-0 



123 



i 21-7 



Subsoil of above. 



3 



1-9 



2-0 



6-6 



1-7 



15-8 



22-5 



7-5 



10-7 



'27-0 



6-2 



10-6 



Surface of drier and 

 more chalky parts of 

 demonstration field. 



4 



8-0 



1-3 



2-0 



•6 



9-0 



10-1 



4-8 



5-6 



14-0 



43-4 



1 lC-5 



Subsoil of abovp. 



5 



2-0 



2-1 



5-8 



•5 





lS-8 



7-5 



15-8 



27-C 



5-4 



161 



Surface of the stubble 

 fields. 



6 



3-3 



2-1 



1-0 



30 



4-5 



14-0 



6-0 



11-0 



27-0 



27-4 



. 15-5 



S'lbsoil of iibove. 



