SPECIAL SUBSOILERS. 105 



We have seen that Guibal, in 1855, had applied this 

 principle to his hoeing rollers. Since then different models 

 have been constructed for surface ploughing. In this type - 

 of machine we may mention that of A. de Souza (1891) 

 Morgan's pulverizer, and the mechanical hoeing machines 

 exhibited by Messrs. Ch. Galland, Grandjon, and Co., at the 

 Agricultural Show held at Paris in 1894. 



Galland and Grandjon's digger consists of a small 

 Guibal roller, in which each pair of steel tines is fixed in a 

 cast-iron disc keyed on a horizontal axle, in the centre of 

 which is a gearing wheel. On the right and left of this 

 wheel are discs, provided with tines, and varying in number 

 according to the width to be worked. At a distance of 

 31 inches above the level of the soil, is a horizontal axle, 

 which a man revolves by means of two handles ; this axle, 

 by means of cog-wheels and chains, revolves the axle of the 

 digger supported at the rear by two wheels acting as a regu- 

 lator for depth. The width worked is 18 inches, the depth 

 4 inches. Certain models proposed for hoeing plants in a 

 line, such as vines, are mounted on a light frame carried by 

 four wheels. The depth worked in this case is 6 inches, and 

 the width 21 J inches. 



Recently, in Italy, the agriculturist, Luigi Pavese, pro- 

 posed a hoeing machine* which may be considered as three 

 Guibal subsoilers, between which shovels worked by a 

 certain movement of rotation pass. We have no precise 

 information as to the work of this machine. 



We may state, in conclusion, that the principle of Guibal's 

 subsoiler is applied to the machine of Paul, of Norfolk 

 (1854), used to open trenches 4ft, lOin. in depth. This 

 machine, which is worked by a horse-gin and chains, is not 

 within the scope of this article. 



* La, macchina Vangatrice Automatica dell' ayronomo Luigi Pavese, 

 VEconomia Rurah, Torino, 24th November, 1899. 



