« AnteriorContinuar »
good land in two years. This is only at the rate of 136 buthels of potatoes (supposing the sack to be 3 bushels) per acre; and it is well known that three times that quantity has been obtained, and 4 quarters 3 bushels and a half of wheat per acre, which would not be reckoned a great crop on any well.cultivated field. It thus appears that neither the crop of wheat nor of potatoes was so great as if the two crops had been obtained in successive years. Nor is it poflible to cultivate the ground at any time so perfe&tly by this half.husbandry, as Mr. Close calls it, as could be done by successive crops of potatoes and grain.
We next find an account of some drilled crops, by Mr. Whitmore. The crop of barley he mencions, which, when drilled in rows at 18 inches distance, yielded fixty bushels of barley per acre, is a very good one. But Mr. Whitmore, who seems to be but a beginning farmer, has already found out one very material defect that will ever attend the mode of culture he is so highly enamoured with, that of giving late and unequally ripe grain. After he has had at least twenty years experience we Thall be much more disposed to follow his practice, than his advice at present. He is certainly in a great mistake, when he supposes the roots of barley extend no farther than fix inches in queft of food. Let him consult Tull's experiments, to ascertain how far the roots of plants extend. .
The gold medal was adjudged to Mr. Thomas Robins, near Tetbury, Gloucestershire, for the greatest quantity of turniprooted cabbages per acre. The certified weight per acre is 13 tons 10 cwt. and 76 pounds *. This, he admits, is a small produce in comparison of turnips ; but he thinks, as it comes into use at a time when food is scarce, the value makes up for the smallness of the quantity. After the turnips were all gone, he found that 200 ewes with their lambs (quere, the average weight of the ewes), could be kept a day on one ton, or twenty hundred weight of these cabbage. The whole value of this crop depends on its keeping as a green food late in the spring. This is the fact therefore that thould be chiefly attended to, that it may be fully ascere" tained.
It appears by a letter from Mr. John Ross, professor of church history in the University of Aberdeen, that the turnipcabbage refifts the severity of the winter in the northern parts of Scotland.
In the subsequent article Mr. Wagstaff, of Norwich, commu. nicates to the Society the result of some experiments which he had made on cultivating unimproved and healthy soils. Those who are possessed of soils which come under that description, fould be cautious how they follow his example; for Thould they attempt it on many soils of that denomination, their * Seventy tons is no very extraordinary crop of turnips.
of a giant feeds of both to be adapted department, is.ad
crops would be nothing. Certainly some peculiarity, not mentioned in Mr. Wagstaff's soil, has been the cause of its producing such fingular crops under the culture he gave it. Ought not the Society to have taken notice of this peculiarity?.
Next follows an account of some experiments on the culture of a giant hemp, which grows to 14 feet high; and of a kind of flax, the seeds of both which were brought from China. But neither of them appears to be adapted to our climate.
The most interesting paper in this department, is an account of the manner of inclofing Rushley island, fituated between Great Wakering in Eflex, and Foulness island; by which two hundred and fixteen acres of land, which were covered every floodtide, but left dry on the ebb, were totally recovered from the sea, and effectually defended against being ever overflowed by it. This work was atchieved by Mr. John Harriot of Rochford, between the middle of June 1781, and the 17th of January 1782; for which he obtained the Society's gold medal.
Though this would have been reckoned a small undertaking in Holland, where much land has been recovered from the sea that was in a situation far more difficult to be cleared of water, and secured from it; yet as such undertakings are little known in this country, we think much praise is due to Mr. Harriot for having ventured so far out of the common road, and so happily accomplished his aim. As we think the method he followed was fimple, natural, and not very expensive, while it, at the same time, bids fair for being effectual, we thall briefly give an account of it to our Readers, hoping it may stimulate some to follow his example : for we know, from our own obServation, that many thousands of acres of valuable land might, be recovered from the sea at a small expence, round the skirts of this our native isle, and its appurtenances.
Mr. Harriot, very judiciously, adopted the kind of fence so particularly described in a book, entitled, Elays relating to Agriculture and rural Affairs * (published, if we mistake not, about ten years ago), and there demonstrated to be the only efa fectual mode of relifting, at a moderate expence, the force of water. This contrivance was nothing more than that of forming the fence in the shape of an oblique inclined plane towards the water. On this principle, Mr. Harriot raised a bank of earth round his little ise, 'thirty feet wide at bottom, seven feet high, and four feet wide at top, giving the advantage of the batter, or flope, full two for one on the outside : that is, every foot in height was drawn in two feet; by this means the violence of the waves is so much abated, that instead of beating, thaking, and tearing the banks, which is the case of all that I have seen, they spend their fury in a gentle curl up the slope of the bank.'
* Sec Rev, vol, lvi. p. 179, for an account of those Essays.
With all due deference to Mr. Harriot's judgment and expen rience, we beg leave to offer it as our opinion, that the Pope here, given to the banks is rather less than perhaps it ought to have been ; but more especially we could be apt to dread, that the height may prove to be rather too small. When a strong wind chances to coincide with a high spring tide, we should think. there was some reason to fear that the sea might be forced over the top of this dike, especially as it must be supposed that it will gradually subside so far as to remain at last of a much less height than it was at first. Had the base been larger, this defect, if it should be afterwards observed, could have been remedied at a small expence, merely by raising it higher ; but in this case, to give much additional height would weaken the fence by bringing it too near to the perpendicular. These remarks we throw out merely with a view to direct others, wbo may afterwards be induced to atiempt undertakings of this sort ; and to remove any objections that may arise to the practicability of effecting such a fence with safety, should it chance (which we fincerely hope will not be the case) that any accident Ihould happen to chis new acquisition,
We hope Mr. Harriot will succeed, by the plan which he has adopred, of at last obtaining freth water in his pond; but he muftnot expect it for some time to be entirely.ro. We do not ap-, prehend that the Caliness he complains of is occafioned by per.. colation through the soil at bottom, seeing the lining preserves water so well from linking through it, but from other very ob- ' vious causes. The whole of the earth that is in this isle has been so long drenched with salt water, that every drop of rain which touches any part of its surface, must wash away fome saline particles, ro that all the water which runs into the pond from the surface of the earth, must necessarily have a saline impregnation. This will be at the first very night, so as to produce no sensible effect; but as part of the water is evaporated by the summer sun, that part which remains will become senfibly affected, so that it will be neceflary once a year to have the pond cleared of all the water, and of the strong saline particles dissolved in it. If this be done, the impregnation will be less and Jess' annually; so that in time, if this mode be adhered to, it will become entirely sweet. These remarks will apply to every kind of cistern, were it even made of lead, or any other substance totally impervious to moisture. In the mean time, Mr. Harriot will do well to be particularly attentive to preserve the water collected from the roofs of his houses. For that purpose let his cistern there be lo large as not to overflow; and so situated as neither to be exposed to the wind nor the sun, to forward the evaporation of it; and if thus preserved, should his ifland produce any considerable proportion of corn, good water in abun
dance may be always obtained. For if the open cistern 'be
The only remaining paper in this department is a long one from Arthur Young, Elg. being a continuation of the experiments on the clustered potatoe, at Bradfield Hall, Suffolk, from the third volume of these Transactions.
From the account here given, it appears that Mr. Young is himself but very little conversant in the culture of this valuable plant; that he has been groping his way, to discover facts that were well known to many persons long before he began his experiments; and that he has not yet attained a due degree of knowledge on the subject he treats. By those who are less skil. ful than himself, these experiments will be read with pleasure; but by such as have acquired much skill in this brancb of agriculture, they will be regarded as futile. The general inference he draws on the whole is a just one; viz, that this plant may be cultivated with profit, perhaps, in every situation; and that it is not yet so generally cultivated as it ought to be. Mr. Young's conjecture about the exhausting nature of potatoes, as a crop, feems not to be well founded.
CHEMISTRY. Under this head we 'meet with only one Paper : an Effay on portable Furnaces, by the Secretary to the Society, Mr. More. After specifying the great utility of portable furnaces, and give ing an historical account of the means that have been adopted for rendering these as perfect as possible, the ingenious Mr. More mentions a very effential improvement which he has made upon them ; viz. to have the body of the furnace lined with a thin coating of fire bricks, properly shaped for the purpose, instead of the luting that Dr. Black of Edinburgh, and some others,
* Twenty-eight inches of rain is about an average of what falls in moft parts of Great Britain in a year. If so, each square foot would yield 4032 cubic inches of water, which is 17 gallons and a half nearly, or 152 gallons for each square yard of roofing, measured horizontally; so that each yard in length of a house which was 21 feet, or seven yards wide, would afford 1099 gallons or about 17 hogsheads a year: of course every 100 yards in length of such a building should afford 17 hundred hogsheads of water; which, fuppofing the pond water to be good for eight months, would leave about 8 hogsheads a day for the consumption of summer, if it were neither fuffered to run to waste por evaporate. Ec 3
have have recommended. This, he observes, can be got at a very small expence in London, and seems to be well calculated for answering every purpose that can be wanted in such kind of furnaces.
POLITE ARTS. Under this head, we find a description of an apparatus for enabling blind persons to perform operations in arithmetic with ease and celerity, by Thomas Grenville, who has the misfortune to be bimself blind. It differs in several respects from Saunderfon's numerical board, and is an improvement of it. The board is perforated full of holes, in exact lines, horizontally and perpendicularly. The lines considered horizontally denote units, tens, hundreds, thousands, &c. reckoning from right to left, as usual. And the perpendicular lines permit the figures to be placed below each other, as is usual in every account. Pegs are made to fit these holes, on the head of each of which pegs is printed the figure (number) it represents, so as that, to a person who has the use of light, the account can be seen at once.
The figures are diftinguithed by the blind person, by means of certain pins placed in the heads of these pegs, which it is unde. cessary for us here to enumerate. Between the rows of boles for these pegs are rows of smaller holes, adapted to receive the bene ends of Imall wires, which perform the part of lines, placed ei. ther horizontally or perpendicularly, as is necessary for any arithmetical operation. The box is formed into proper divia Lions for holding the pegs and wires, and is doubtless a most useful apparatus for those whom it was intended to allift; for there can be no doubt but that any blind person, with a little attention, by means of this simple apparatus, may perforas every arithmetical operation that could be performed by him if he had the use of fight.
We cannot help regretting that the Society did not cause the plate, which illustrates it, to be so engraved, as that the parts of it might be felt by the band (in the tile of paper mache) for the use of the blind, who may be desirous of forming an idea of it. This could have been done by means of printers' lines, and dots, even without engraving at all; for by means of these, if done upon dry, thick paper, much pressed in the working, the lines would have been distin&tly perceptible by the finger.
MANUFACTURES. Under this head, we meet with an interefting account of the manner of managing filk-worms in England, by Miss Henrietta Rhodes, of Cann Hall, near Bridgenorth; in which are ascertained several important facts relating to this animal, that were not before sufficiently, if at all known, and will open views to the speculator, big with future consequences to the prosperity of the manufactures of this country.