524 AGRICULTURAL IMPLEMENTS., TOOLS, ETC. 



more manifestly in the calculation by the hundred, it will not 

 be found to exercise the same influence over the decennial 

 average, according to well-known statistical law that certainty 

 in calculation from numbers is increased in proportion to the 

 plurality of the instances from which the inference is derived. 



In the originals, hurdles are frequently reckoned singly, with 

 a statement that the cost was plus or minus in toto, than the 

 single valuation. Sometimes they are reckoned at so much in the 

 aggregate. These notes of plus and minus cost are so frequent, 

 and involve so many incongruous fractions, that unless a large 

 quantity had been taken in the table constructed from these 

 facts, a real rise and fall in the market rate would have been 

 distinguished with difficulty. 



The reader will recognize, on consulting the table of de- 

 cennial averages, that the same course of prices is discoverable 

 in the rate at which hurdles are purchased as was found in so 

 many other articles of manufactured produce. In the first 

 ninety years we see that the rate is enhanced during the years 

 1311-1320, and had it not been for the total deficiency of 

 information for three years in the preceding decade, it cannot, 

 I think, be doubted that a similar, though not an equal exaltation, 

 would have been discerned in the first ten years of the four- 

 teenth century. The price declines anew, though not to the 

 old level, in the thirty years following; the last ten of these 

 years, though the lowest of the three decades, being a little 

 raised by the high prices of 1349, 1350. 



But on the other hand, the rise is great and permanent after 

 the Plague, and, as usual, highest in the twenty years 1361- 

 1380, falling again in the last twenty years of the fourteenth 

 century. Thus on the whole, the price of hurdles is exactly 

 doubled on comparing the averages of ninety and fifty years, 

 a fact which I think implies that the labour of hurdle-making 

 was one of those the remuneration of which was very scanty 

 in the earlier period, but which was now proportionately in- 

 creased in accordance with the law so often adverted to that 

 a sudden increase in the rate of wages, all impediments to the 



