MEDI.l-.VAL AND MODERN PRODUCE MARKETS 831 



A merchant was thus enabled to secure a considerable supply of 

 grain at harvest without immediate outlay. 



Speculation in produce is primarily founded upon the exact 

 determination of the relation between the visible and the total 

 supply. In modern times, statistical information is available 

 which confines individual opinion within fairly narrow limits. 

 In the Middle Ages, the visible supply constituted a smaller 

 portion of the total supply, and the total supply was hardly 

 more than a matter of pure conjecture. The margin of possible 

 gain for the professional trader was thus considerably increased. 

 The nature of speculative operations was also affected. The great 

 maneuvers of the modern markets are founded upon superiority 

 of knowledge of conditions affecting both demand and supply. 

 General sources of information are so considerable that the 

 trader's gain is based upon acquisition of more precise details 

 and upon skill in drawing deductions from his facts. The his- 

 tory of the famous Patten wheat deal and of the Hull deal in 

 cotton are interesting illustrations of modern successes. In the 

 late Middle Ages the ignorance of the total supply was so com- 

 plete that the spectacular gains of the merchants were made by 

 refraining from giving the public any enlightenment as to total 

 supplies and studiously creating misapprehensions. Some of the 

 most systematic maneuvers of this type occurred in the vicinity 

 <>!' Paris in the latter half of the seventeenth century, just before 

 the passing of the old order. A large portion of the grain sup- 

 ply of Paris came by water from the upper Marne and Seine. 

 These merchants shipped their grain from the more distant 

 sources of supply, and then, instead of allowing the boats to 

 come through t> Paris, they stopped them fifteen or twenty miles 

 outride and unloaded there. Sometimes there was a pretense of 

 holding the grain for conversion into flour; most frequently it 

 was merely stored in secret. The arrivals at Paris could be con- 

 siderably diminished. Rumors would then spread of relative 

 dearth in the Seine and Marne valleys. Prices would rise. The 

 supplies in the vicinity could then be sold at the advanced prices 

 it tin quantities released from store at any one time 

 considerable. Such a I >n of the market was made possible 



