May, 1921. 



SCIENTIFIC AGRICULTURE 



207 



X was raised up — would it not tend to raise t^e 

 horse off its front legs? I think so. (See Figure 16.) 

 The point of attachment of the tug to the bame, the 

 point of attachment of the clevis and the centre of 

 resistance of the plow bottom should all lie in a 

 straight line. The same applies to engine plows. A 

 high drawbar on a tractor and a low drawbar on a 

 plow connected with a short stiff hitch will result in 

 one of two difficulties: 



1. Ill a poorly designed engine; the front wheels 

 will be raised off the ground. 



2. The front furrow wheel of plow will be rai.sed 

 and thus lose the tractive efficiency required to raise 

 t^ie power left plow. 



Do not be misled by the above figures. On a steadj' 

 load like a plow' when the tugs are never slack, a horse 

 will exert, a steady pull of from one-tenth to one- 

 eighth of its weight. This .seems very little. How 

 much does it take to pull your gang plow? I cannot 

 tell you exactly; it will depend on the soil, the depth 

 and the adjustment of t.iie plow amongst other things. 

 But it will be between 400 and 1.000 pounds. ThLs 

 seems very little, and I am stire k far below what 

 you would have estimated. Had I asked you, you 

 might have said 2.000 or 5.000 pounds. In the heavy 

 soil found along tlie iSoo Line in Southern Saskatche- 

 wan, a three furrow disc was t-ested and found to be 

 taking a steady drawbar ptill of 1,350 pounds. This 

 was a very hea\'>' load for t/ie seven horses. This 

 pull is measured on a scale that has a capacity of 

 2,000 pounds. It is callerf a Dynamometer. The cut 

 showing this instrument may interest some of the read- 

 ers of this article. It should be an educational feature 

 of every plowing match held in Western Canada, be- 

 cause it helps to solve many difficulties and decide 

 many discussions. Farmers are interested. 



The Winnipeg Motor Contest, results show t^iat an 

 average pull of 700 pounds was required to pull a 

 14-in. plow 4 in. deep in breaking. The following 

 results from a test at Saskatoon shows how different 

 kinds of sod varied : 



Western Rye 358 pouiuls 



Brome 405 pounds 



Alfalfa 700 pounds 



Mixed Hay 425 pounds 



These tests were not repeated' but they show that 

 there is a considerable difference. The walking plow 

 used was cutting a furrow 13 inches b.v 4 inches. 



The reason w,iiy plowing tandem is desirable is that 

 the centre of the hitch can be in the same line as the 

 centre of the plow. Tliis centre line in a gang plow 

 is 19 in. from the furrow wall as we saw in the last 

 article on this subject. If you hit«h away to t^e left 

 hand corner of your plow, as you must when you- 

 j)low four abrea.st, your plow tends to take up the 

 position as shown in Figure 3. 



Reter to figure 9A and you will see what happens 

 when you hitch to one side of your .stoneljoat — it 

 pulls at an angle. That's right, and so does your plow. 

 With a three-horse outfit the position of the hitch is 

 decided by the distance from the furrow wall to the 

 centre of the large doubletree, but bear in mind that 

 the centre of the plow is still 19 in. from the land side. 

 Eveners Which Remove Side Draft. 



I hear someone say tliat t,iiere arc eveners on the 

 market that will allow you to use four horses abreast 

 and remove sidedi-aft. 1 have never seen them .vet, 

 and no one selling such a device has ever convinced 



me that they do remove side-draft, because they don't. 

 Well, the plow pulls .straight. If you hitched to one 

 side of your stoneboat and put a brace across to one 

 comer, it would pull straight. Wliat would pull it 

 s-traight? Wliy, the brace, of course. I have no quar- 

 rel to pick with anyone selling such eveners, if they 

 can. But you as a practical man can prove to your- 

 self that they do not remove sidedraft. Take a few 

 pieces of lath and make a model. When you pull 

 in the direction of the arrow on the right, there Ls 

 a pressure in the direction of the arrow on the left. 

 With four abreas-t you give your front furrow wheel 

 lead to -the land in an endeavor to hold your plow 

 straight, and the rear furrow wheel lead away from 

 the land for the same reason. It takes power to hold 

 a plow straight. Your argument, about the horses 

 being closer to their work breaks down when you think 

 of the power waited in holding the plow straigjit. 

 Actual trials have shown that in the distance the lead 

 team is away from the plow, the weight of the hitch 

 is about all tf\at is added to the draft. The weak point 

 lies in the fact that the lead team has not as good trac- 

 tion. The angle of the tugs is less than in the case 



;7afs A Hinn O/ce ms ^UMINATE: c^J//$Tf1/BUT£ 



Figure 9B. 



of the wheel teams. Stand at tlie side of a tandem 

 outfit and you will notice the tugs of the wheel 

 team are at right angles to the hames. What about the 

 lead teams? The angle of the tugs is less. But do 

 not overlook this very important point : the plow 

 pulls .straight, and the team has an easier day, es- 

 pecially in the hot weather. Wlien a man tells you 

 that a team cannot pull a bag of wheat at the end 

 of a 100-foot rope, a.sk ^lim if he ever tried it. It is 

 a common argiunent. Remember thati the distance a 

 lead team is away from the plow should never deter 

 you from plowing tandem. 



If you insist on plowing with four horses abreast 

 you will find that there is a decided twi.sting action 

 tending to swing the plow towards the plow ground. 

 To overcome this you will notice that the front furrow 

 wheel has to give "lead" to the "laud"' and the rear 

 furrow wheel "lead" away from the "land". It 

 takes power to overcome this t\vistiug action. (R^?fer 

 to Figures lOA and lOB.) Would a wagon pull 

 harder if it had wheels like a disc harrow? I t,iiink 

 so, and so do you. 



The following may be of interest: The pull on tugs 

 has a tendency to lift the plow out of the ground 

 and some other force must overcome this lifting ten- 

 dency or the plow will not stay in the ground. If 

 there is not enougji suction to overcome this lifting 

 action of the hitch, you must increase the suction. 



