92 FIELDS, FACTORIES AND WORKSHOPS. 



recently the French Professor Aimd Girard undertook 

 a series of experiments in order to find out the best 

 conditions for growing potatoes in his country.* He did 

 not care for show-crops obtained by means of extrava- 

 gant manuring, but carefully studied all conditions : the 

 best variety, the depth of tilling and planting, the dis- 

 tance between the plants. Then he entered into 

 correspondence with some 350 growers in different parts 

 of France, advised them by letters, and finally induced 

 them to experiment. Strictly following his instructions, 

 several of his correspondents made experiments on a 

 small scale, and they obtained instead of the three tons 

 which they were accustomed to grow such crops as 

 would correspond to twenty and thirty-six tons to the 

 acre.t Moreover, ninety growers experimented on 

 fields more than one-quarter of an acre in size, and more 

 than twenty growers made their experiments on larger 

 areas of from three to twenty-eight acres. The result 

 was that none of them obtained less than twelve tons to 

 the acre, while some obtained twenty tons, and the 

 average was, for the no growers, fourteen and a half 

 tons per acre. 



However, industry requires still heavier crops. 

 Potatoes are largely used in Germany and Belgium 

 for distilleries; consequently, the distillery owners try 

 to obtain the greatest possible amounts of starch from the 

 acre. Extensive experiments have lately been made 

 for that purpose in Germany, and the crops were : nine 

 tons per acre for the poor sorts, fourteen tons for the 

 better ones, and thirty- two and four- tenths tons for the 

 best varieties of potatoes. 



Three tons to the acre and more than thirty tons to 

 the acre are thus the ascertained limits ; and one neces- 

 sarily asks oneself: Which of the two requires less 



* See the Annales agronomiques for 1892 and 1893 ; also Journal ftci 

 Economistes, feVrier, 1893, P- 2I 5- 

 t Fifty to ninety tons per hectare. 



