2l8 



Journal of Agriculture, Victoria. 



[lo April, 1911. 



keeping it flowing for forty-eight liours, wliereas in sanely soils the full 

 quantity would complete the work in twenty-four liours or k-ss. A good 

 method of ascertaining the percohition (jualities of soils is to sink a series 

 of holes varying from 6 inches to 18 inches or more at short distances apart 

 and fill them with water. The deptli of the holes will be governed by the 



^^„^rrrrrr, character of the soil and subsoil, 

 and the time taken for the water 

 to disappear will serve as a 

 guide. 



After filling with water, cover the 



■^~ frrrrrTTr-rrrTrrrn- ^ rrrrmr-rrrTTrn 



64. TESTING SOIL FOR PERCOL \Tiox. holes to reduce evaporation losses, 

 in the majority of cases of Goulburn "\'alley land, a 6-inch hole would just 

 reach or slightly penetrate the subsoil and a good idea will be given of the 

 adaptability of the surface soil for irrigation, while the deeper holes will 

 similarly test the subsoil. The extremes of absorption will necessarily 

 lie between clay and sand, Ijut it has yet to be determined where, within 

 those limits, the medial lint* shall t:)e fixed. ^^'here other 

 physical conditions obtain, such as in the sand ridges of the 

 Mallee, the holes will of course be made deeper and each par- 

 ticular district will have its separate co-efficient. As irrigation 

 is practi-sed in the warm months of the season, experiments 

 should be made in similar conditions. If made after satura- 

 tion by rain or irrigation they will be valueless. 



Another point that has yet to be investigated is the effect 

 on irrigated soils of continuous watering. Analy.ses should 

 be systemadcally undertaken at varying intervals between suc- 

 cessive waterings to determine the extent and duration of 

 saturation, and, if synchronous analvses are made of un- 

 irrigated soils, reliable data for future guidance will be 

 obtained and standardization will be possible. 



It may be of interest to some to point out some easy and 

 inexpensive means bv which lower strata may be investigated. 

 Apart from analytical value, a readv means will be furnished 

 of fixing sites for dams, tanks. foun<lations, &c., without the y^/^. 

 expense of first sinking trial shafts. The simplest tool is ag_ boring 

 frobe, and is applicable only to soft .soils easily penetrated. .\uger. 

 It consists of any convenient length of. say |-inch piping, fitted 

 at one end with a spike made to .screw into the socket. It is operated by 

 merely " jumping " and it is surprismg how deep it may be made to enter. 

 It cannot bring up samples, but rock or other bottom is easily located. 

 Another means of investigation is bv boring. A cheap set of boring tools 

 m,ay t)e made from |-inch pipe and a 2-inch carpenter's auger, with which 

 depths of at least 50 feet may often be attained and 

 samples of the strata traversed, .secured. Cut the stem of 

 the auger at the point marked A, and '"' upset " the cut 

 ends sufficiently to take the same thread as f-inch piping. 

 Bore a hole in the "worm," where shown, and cut awav 

 66. CUTTING 3 V-shaped piece at the end leaving it as in No. 66. 

 END OF AUGER. ]3,-.-,^v the points out and temper so that they project 

 :|dnch bevond the straight of the barrel, forming what is known 

 as a " swallow tail," the object being to secure a good cutting edge 

 and give clearance to the auger. U.se similar piping for boring 

 rods and ha\e short lengths of 2 feet, 4 feet, and 6 feet for con- 



