FOR AMERICAN VINES. 43 



increases its cost by 12. Up to the present no horse-gin 

 has had this additional device, and, if the winding of the 

 cable is not always very regular, this defect, however, is not 

 of much importance. It is, as a matter of fact, easy to 

 insure good winding. All that is necessary is to moderate 

 the unwinding during the carrying back of the plough to 

 the starting point, so as to prevent the last turns from 

 becoming slack and overlapping one another. If this pre- 

 caution is followed, defective winding never occurs. 



The Pelous gin, with 274 yards of cable 0'6 inch in 

 diameter, costs 32. With a cable guide, it costs 44. It 

 hauls a strong trenching-plough, with a seat for the plough- 

 man, which costs 28. 



Working. This machine works like those already 

 described. 



MECHANICAL YIELD OF HORSE-GINS. 



It is interesting to know the mechanical yield of gins 

 that is to say, to estimate the loss of power due to friction 

 and other detrimental resistance of the machine, to find out 

 the ratio between the moving power (horses) and the 

 resistance (plough). Experiments were made by Chabaneix, 

 of the School of Agriculture, Montpellier, in August, 1887, 

 at Candillargues, with Beauquesne's gin. 



The large traction dynamometer (power-gauge), of the 

 School of Agriculture, was fixed to the bridle of the plough, 

 to measure the resistance offered by it. Another smaller 

 dynamometer, belonging to the school, was interposed 

 between the swingle-bar and the pole to measure the effort 

 developed by the animals. The ratio between these two 

 expresses the mechanical yield of the machine and the 

 difference, the detrimental resistance. Two consecutive 

 trials were made, and gave the following results : 



Detrimental resistance : 



1st trial ... 11'8 per cent, of the total motive-power. 

 2nd ... 10-3 

 Mean ... 11 



Yield of the machine : 



1st trial ... 88'2 per cent. 

 2nd ,, ... 89-7 

 Mean ... 89'0 ,, 



These figures show that the yield of the machine is con- 

 siderable, and the losses due to the mechanism almost 



