Vol. XII. No. 301. 



THE AGRICULTURAL NEWS 



359 



AGRICULTURAL ENGINEERING. 



NEW TAPPING KNIVES FOR 

 RUBBER TREES. 



It is well known that one of the objections to methods 

 that are commonly employed for tapping Gastilloa is that the 

 trees never fully recover from the wounds left by the tapping 

 process. According to the India Rubber World (October 1, 

 191o), this ditKculty can be got over by employing a new 

 knife that has just been invented which, instead of cutting 

 out a piece or .strip of the bark in the usual way, merely 

 raises the bark from the tree to a sufficient extent to permit 

 the escape of latex. After the operation, the bark is closed 

 down to its original position and allowed to grow fast. It is 

 stated that very little scar is left, and that the process is of 

 great advantage, since it permits a continuous tapping of the 

 tree immediately above or below, or even directly on top of 

 the previous cut. From the illustration given in tlie India 

 Rubber World the instrument is seen to resemble somewhat 

 a semicircular comb fitted with a handle One e.xcellent 

 feature of this new knife is that it is provided with a 

 movable gauge attached to the thumb screws behind the 

 cutting edge, so that the teeth can be quickly adjusted to the 

 proper dejjth for a tree of any age. 



Another interesting knife described at some length in 

 the Ind^a Rubber Journal (September 13, 1913) is one 

 which is constiucted for cutting along the ."ides of the 

 shallow chani.ol in the cuter b.ik of ilevea lubber trees. 

 This invention comprises the formation on the blade of two 

 or more slots, which extend to one end of the blade. The 

 middle area or tongue in the blade thus formed by the 

 space on each side of it, is bent in a concave fashion so that 

 each edge 'stands proud of the portions of the blade on each 

 side. These turned out edges are used for paring the cut, 

 whilst an arrangement of guards operates to prevent the front 

 cutting edge of the purtions of the blade each side of the 

 concave tongue, from cutting into the cambium at the 

 bottom of the groove in the tree. 



INTRODUCTION OP MOTOR PLOUGHING 



INTO ST. CROIX. 



In order to plough the land deep and prepare it early, 

 ■with a view to the conservation of moisture, the Director of 

 Agriculture, St. Croix, D.AV.I , advocated the use in that 

 Colony of motor ploughs. As the result of discussions at 

 meeticgs of the Agricultural Society, the Government 

 decided to vote the necessary funds to enable the Director of 

 Agriculture and a representative of the Agricultural Society 

 to visit Cuba and the United States, in order to investigate 

 the question of motor cultivation on the spot. 



OnsEttVATIOXS IN' €U1!.\, I.OVI.SI.\N.\ AXD TE.\.\S. 



Gasolene motor ploughs were found in extensive use in 

 Cuba on one large sugar estate; the weather, however, had 

 been too wet to allow of the ploughs being seen at work. 

 The engines in use were big four cylinder gasolene machines, 

 and the owner expressed himself well sati-sfied with the work 

 they performed. Travelling to Louisiana, the visitors found 

 the same kind of four cylinder traction engine and plough used 

 in cane cultivation there. The machine was observed at work 

 harrowing land, which was laid out in a series of banks and 

 furrows. A disc harrow was used, and the engine went across 

 the banks ijuite easily. Later the engine was seen at work 

 in a field which was a mass of weeds, and these checked the 



plough frequently. The owner explained that this was dupto 

 his not having the proper coulters on the machine. The- 

 plough was working to a depth of about 7 inches, and six 

 bottoms were drawn by the motor at one time. The engine 

 went over unevenness in the land with great ease and without 

 excessive jerking, and it negotiated the ditches between the 

 fields quite easily by having them filled up with rough logs of 

 wood at the places where the engine crcssed. The plough 

 was stated to have done 10 to 15 acres a day, and it was 

 believed it could do more if the fields had not been so small 

 (about .5 acres). 



The delegates next proceeded to the State of Texas where 

 they saw one of the 'Twin City' four- cylinder gasolene traction 

 engines at work, ploughingsome of the stitlest soil in the United 

 States. The machines were doing excellent work, ploughing 

 a stift', clay soil filled with the interlacing roots of the Texas 

 'mesqnile' tree, to a depth of 8 or 9 inches. The plough 

 used with the engine was of special design and had only 

 three bottoms, but it weighed 7,000 lb. The engine drew 

 this huge plough irresistibly through the tough root-bound 

 soil, tearing through branches 2 to 5 inches in diameter with 

 the greatest ea.s-. Occasionally, a particularly stiff stump 

 would cau.se the plough to resist so mucli that the huge 

 wheels of the engine would revolve without moving it. 

 Then the man in charge would back a few inches and jamb 

 on the clutch, rushing the machine forward, and after a few 

 trials like this, the plough would pull through. The engine 

 ploughed 7 to 8 acres a day of this stiff 'mesquite' land to 

 a depth of 8 or 9 inches. Eight gallons of gasolene and 

 i-gallon of lubricating oil were used per acre. 



As the result of the visit which provided the above 

 interesting observations, the Danish Government have voted 

 the money for a motor ploughing outfit as already noted ia 

 an an article on motor cultivation in the A'jriculturnl Newx, 

 Vol. XII, No. 294. The outfit was expected to arrive about 

 the end of July 1913. 



TRI.\L OK NKW IMPLEMENTS. 



As well as in the introduction of motor traction into the 

 Colony of St. Croix, the Danish Government have exhibited 

 very considerable enterprise in the matter of importing new 

 implements. The following machines are now in the pos- 

 session of the Department of Agriculture: a corn and cotton 

 planter, a Cuban 22plough, a Cuban double mould-board 

 fluke, a Magnolia lister, a double mould-board plough, 

 two subsoil ploughs, a 'Secretary' disc plough, a deep- 

 tillage 'Stag' sulkey plough, and a potato digger. Nearly 

 all these implements 'aave been found to work well, and 

 their use has been demonstrated to planters. The work of 

 the Cuban 22-plough has been particularly admired, and 

 several of these implements have been imported at the 

 request of planters. The corn and cotton planter has also 

 been purchased by several estate owners. Five or G acres- 

 of cotton can be planted in one day with one of these 

 machines. The Verity double mould-board plough is 

 stated to be excellent for opening deep furrows for manure 

 or for planting cane, and the Cuban double mould-board 

 fluke is useful for cleaning out the furrow after the 

 Verity plough has done the first work. The 'Secretary' disc 

 plough appears to be capable of performing useful work in 

 cane cultivation, and it has the special advantage of a sub- 

 soil attachment which follow.i in the furrow made by the disc. 

 A G-acre piece of very heavy clay land has been ploughed in 

 St. Croix by this machine; the soil was turned over with the 

 disc some 8 inches, and the subsoil attachment opened the 

 land some 4 or ") inches below this. 'With the deep tillage- 

 'Stag' sulkey plough, stiff land, it ia stated, can be readily 

 ploughed 17 inches deep. 



