208 



SCIENTIFIC AGRICULTURE 



May, 1921. 



Tests made at one of tlie Experiment Stations show 

 that hitching a QV^-foot chain between the end of the 

 plow beam and the evener made a saving of 6 per 

 cent in t;ie draft of the implement (a 14-iii. walking 

 plow) while a ISV^-foot chain made a saving of 8 per 

 cent in the pull of the plow. You see when you 

 increase the length of the hitch, you decrease the 

 lifting action, and, therefore, reduce the power by 

 the amount necessaiy to overcome this lifting action. 

 (See Figure 17.) We know this is not a practical 

 experiment, but remember a very .short hiteli is not 

 necessarily the best. 



With a short beam plow the tendency to lift the 

 plow out of the ground is greater. The suction has 

 to be increased. Two forces, one lifting out, the other 

 pulling it in, take power, therefore the experiment 

 just referred to is interesting. 



The draft of plows varies in different soils in ap- 

 proximately the order of the following: 



Sandy soil, 2 to :5 pounds per square inch of cross 

 section. 



Sandy loam, Tj pounds per square iiicu of cross 

 section. 



fact that the loadline of a two furrow 14 in. plow 

 is approximately 19 inches from the furrow wall. 

 Then for a three furrow plow we find the load-line to be 

 the load-line of the centre plow, or 26 inches from the 

 furrow wall and with a four furrow plow we find it is 

 33 in. over. The tractor is nearly always wider than the 

 plow. The centre of draft-line of the tractor is midway 

 between the drivers, and the wheel next to the furrow 

 has to be 6 or 8 inches from the edge of the furrow. 

 What is t,iie result? The centre of the tractor and 

 tlie centre of the plow are not in the same straight 

 line and again we have sidedraft. Since the small 

 tractors can only st-and very little sidedraft we have 

 to liiteh very close to the centre of the tractor. This 

 places a considerable proportion of the sidedraft on 

 t^e plow. By means of a solid triangular bar hitch, 

 this sidedraft is taken care of, but not eliminated. 

 The walking plow, the gang plow and tractor plow 

 must be pulled straight to the land, not at an angle, 

 if good plowing is to be the result. They must set 

 right. They must be operated intelligently. When 

 on a grade, the effective drawbar of the tractor is 

 lessened by 1 per cent of the combined weight: of t^e 

 tractor and load, for every one foot of rise per 100 

 feet, or for every 1 per cent grade. For example, 

 let us suppose that the weight of tractor ready to 

 work with an operator and three furrow plow is 

 7,600 pounds. To climb a 10 per cent grade with this 

 outfit would require an additional amount of power 

 equivalent to a pull at the drawbar of 760 pounds. 

 This means practically dropping a plow. Let us do 

 all we can to pa.ss along any information we may 

 liave to give. 



In conclusion, let me assure you that the subject 

 of plows and plowing is one of vital , interest to t/ie 

 farmer who is a good business man, and it is hard to 

 know where to end a diseus.sion such as the foregoing, 

 and so to err on the safe side, I will draw it to a 

 close, anil hope 1 have left enough material with you 

 to interest you more in this important question. 



Figure 18. 



Prairie sod, 15 pounds per square incli of eros.s- 

 seetion. 



Gumbo, 20 pounds per square inch of cross section. 



Example : If you have a furrow 14 in. wide and 

 5 in. deep, you multiply 14 x 5, equals 70 square 

 inches and if it takes 700 pounds to pull the plow 

 there will be 10 pounds of drawbar pull required 

 for everj' square iuc/i of cross sectional area. 



So many small tractors are now in use that we feel 

 justified in devoting a little space to the hitch prob- 

 lem as it affects them. The following information 

 and the illustration are applicable in a general way 

 to all makes. Reference to Figure 10 will recall the 



THE JUNE ISSUE. 



The June issue of iScieiitific Aynctilture will be ne- 

 cessarily delayed and may not be mailed from the point 

 of publication until June 30th. It will contain a full 

 report of the Winnipeg Convention. 



As this issue goes to press, general plans for the An- 

 nual Convention are practically complete. Local details 

 will be attended to by the General Secretary, who will 

 arrive in Winnipeg on June 5th. The co-operation of 

 President Bracken of the Manitoba Agricultural College 

 and his staff, is assured. The Lieutenant-Governor of 

 Manitoba, tlie Minister and Deputy Minister of Agri- 

 culture and- the Mayor of Winnipeg have agreed to at- 

 tend the Convention and to address those jiresent. There 

 is every -indication of a successful and enthusiastic 

 meeting. 



A social programme has yet to be arranged, but this 

 can best be planned at a later date. The close of a 

 strenuous period is the time for entertainment and com- 

 plete relaxation ami this will lie ])rovided on the even- 

 ing of June 17th. 



The General Secretary, and the members of the Dom- 

 inion Executive Committee, wish to urge the attendance 

 of every member who can po.ssibly be in Winnipeg on 

 June 15, 16 and 17 next. 



