FARMERS' REGISTER— fc:XPERIi\lENT ON POTATOES. 



505 



planted potato seed of the red-nosed kidney spe- 

 cies, and m the remainiatr two of the apjjle kind. 

 Those Jie earthed up in liie usual way: in these 

 eartheti drills the produce was 6 lbs. (about 10 per 

 ceni,) less than in ibur corresponding ones un- 

 earttied. In all those drills (which were 30 inches 

 apart,) the sets were placed from 10 to 12 inches 

 asunder. The treatment of the unearthed drills 

 may be thus stated: they were dug at bottom 12 

 inches deep, and left hall" full of the crumbling 

 clods; on these the potatoes were laid, and then 

 covered about three inches with dung, over wliich 

 an inch of fine earth was drawn. When the 

 shoots were sufficiently high the clods \vere bro- 

 ken fine and closed about the stems, and the ground 

 in the intervals dug deep and fine as possible, and 

 left perfectly flat; this was the only tdlage which 

 the unearthed potatoes received. The produce 

 was about 150 barrels* to the acre. 



Experiment 2.— In order to determine at what 

 distance in drills 30 inches apart, it is advantageous 

 to plant the sets, Mr. Robertson proceeded as Ibl- 

 lows: — 



In a piece of ground of sixty square yai'ds (not 

 yards square,) he planted eight drills of a new 

 seedling cup potato at 30 inches distance; these 

 drills, nearly 9 feet in length, he planted at the 

 distance above stated as Ibllows: 



eft. 



Gross produce, 1 15 2 



Which is about 228 barrels, or 28 tons 10 cwt. 

 to the Irish acre, accurately weighed. This enor- 

 mous produce was from an alluvial soil light and 

 deep. 



Experiment 3. — To ascertain the result of giving 

 unlimited room to the potato, and the depth to 

 which the roots would run if unrestrained. 



On a piece of ground trenched upwards of three 

 feet, Mr. Robertson planted eight whole potatoes, 

 each three feet apart in the row, with unlimited 

 room to grow at each side. The produce was six 

 stones, and the fibres were traced downwards 3 

 feet, the space they occupied being equal to tliat of 

 two drills in Experiment 2. 



Experiment 1 proves the inutility of earth- 

 ing. 



Experiment 2, gives an interesting demonstra- 

 tion ol the advantage of free access of air, the 

 outside drills giving such superior produce, and the 



*The Kilkenny barrel contains 20 stone of 14 lb. 

 Vol. 11—38 



advantage (25 per cent.) of the double stemmed 

 ones over the single, at the same distance, proves 

 (combined with the other circumstance) the truth 

 of Mr. Knight's theory, that, in proportion to the 

 abundance of its foliage, and the free access of 

 air and light, will be the productiveness of the po- 

 tato. 



From the similarity of produce in the corres- 

 ponding drills of Nos. 2, 4, and 6, and in Nos. 

 3, 5, and 7, it would appear of litUe importance 

 at w4iat distance the sets are placed in the drills, 

 provided they have sufficient room to spread at 

 each side, and the extent of this must be regulated 

 by experience. 



It is of the highest importance, however, that 

 the ground should be deeply worked and highly 

 pulverized; for the potato fibre is extremely delicate, 

 and cannot penetrate through a hard unyielding 

 soil, though it will nni freely through that which 

 is loose, and occupy the pulverized' intervals be- 

 tween the drills. 



Mr. Robertson deems it highly absurd, in shal- 

 low soils, to heap on the top of the potatoes, 

 where it affords no nutrime^nt, the earth which, if 

 left within the range of fibre, would feed it. How- 

 ever, it is to be remeinbered, that some species of 

 potatoes strike upwards, cups for instance, (though 

 it appears that Mr. Robertson used these in thia 

 experiment,) and in such case earthing is proba- 

 bly most useful. jlpple potatoes have a dovv^n- 

 ward tendency, and therefore may not require 

 moulding. The species under culture, and the 

 nature of the soil, should also materially influence 

 the farmer as to the disposition of the manure un- 

 der or over the set. It is obvious that (on a dry 

 and porous soil in particular) in the culture of 

 cup potatoes, the vegetating tendencies of which 

 are to the surface, it is injudicious to place the ma- 

 nure under the sets. 



The Carlow farmers in general place tlie pota- 

 to set under the manure, by which mode the young 

 plant has a nutritious, waim, and protecting cover- 

 ing, during its incipient f^rowth. The av^erage 

 produce of the poor man s potato crop, however, 

 from want of adequate manure, and from the con- 

 tinued exhaustion of the ground, is not 80 barrels 

 to the Irish acre. 



When we read of the produce obtained by Mr. 

 Robertson, and of the enormous quantities raised 

 by Mr. Knight, it is truly lamentable that the 

 poor Irish farmer who most needs the supply falls 

 so miserably short of it. 



FRENCH WEIGHTS AND MEASURES. 



[The followiiTg account of the plan of the modern 

 French weights and measures, will be necessar}' for 

 the readers of many of the articles translated from the 

 French for the Farmers' Register, and maybe useful 

 for general reference. It is extracted from different 

 parts of Brewster's Edinburgh Encyclopcedia.] 

 French measures. 



On the 1st of August, 1793, the National Con- 

 vention resolved to adopt an uniform system of 

 weights and measures; and, in the year 1795, a 

 new system was established by law, which had 

 been drawn up by the Academy of Sciences, who 

 were entrusted with the prosecution of it by the 

 Constituent Assembly. 



Ths ftmdamental urut of the metrical i«vetcra of 



