406 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



tile, and one was adopted made expressly for the purpose, and 

 known as the "Hibberd potato tile." This is a foot wide and 

 fourteen inches long, being in the form of a low, flat-topped 

 arch, four inches deep in the centre. These tiles are laid 

 down in lines four feet apart, on hard ground, and as the sets 

 are laid on the tiles they are covered with earth from the in- 

 tervening spaces. The result is a series of rounded ridges, 

 so far separated that the plants enjoy an abundance of light 

 and air ; lodgment of water is impossible, and in the event 

 of a sudden lowering of temperature when the tubers are rip- 

 ening, the storage of earth-heat below the roots tides the 

 crop over the time of danger, and prevents that engorgement 

 of the tissues which constitutes the first stage of the disease 

 and the nursery for the fungus. The intervening spaces 

 should be deeply dug and liberally manured, and planted, in 

 the garden, with suitable crops, such as celery, dwarf pease, 

 brocoli, etc., while in farm practice it may be best to leave 

 the furrows open, because the sorts of potatoes selected would 

 profitably utilize the light and air, and in strong land really 

 meet across the furrows. 



In response to the question whether the operation will pay 

 in practice, Mr. Hibberd remarks that the outlay at first is 

 considerable, and that the tiles, even in England, can not be 

 obtained at less than $30 to $40 a thousand, or at the rate 

 of about $350 per acre ; or, if laid a yard apart, the cost would 

 amount to $300 per acre. 



Mr. Hibberd's experiments with these tiles have been con- 

 ducted for nearly ten years, and he is emphatically of the 

 opinion that, while in hot and dry seasons there is compara- 

 tively little advantage over the old method, yet in a majority 

 of seasons, and always where these are unfavorable, the yield, 

 in a very short time, is so much greater as to more than re- 

 pay the cost of the tiles and furnish a handsome profit; and 

 although he confesses he has occasionally taken diseased po- 

 tatoes from the tiles, yet in several seasons he obtained a 

 very satisfactory crop when others had none. 



PEIZE FOE AN ESSAY OX THE POTATO DISEASE. 



x 



The Royal Agricultural Society of Great Britain, through 

 the liberality of Earl Cathcart, was enabled to offer a prize 

 of 100 for the best essay on the primary cause of the potato 



