« PoprzedniaDalej »
soil in large dressings. The shell-marl formed, as we useless to observe here, that it is precisely in this same are aware, of the debris of cockles, had become incor- hothouse of the College of Medicine that M. de Luca porated with the earth we are about to speak of, in has made his interesting experiments upon the nitrificaconsequence of an application of 70 cubic metres per tion of potash by the elements of the atmosphere. hectare. In 1 kilogramme of this shell-marl, recently Whether the nitrates, of which I have given the large taken from the pit, I was not able to detect the least dose in the soil of bothouses, have their origin in trace of nitrate.
the atmosphere, or that they may be formed as the reA very white marl, from La Chaise, near Louzouer sult of modifications which the organic matters in ma(Loiret), examined immediately after its extraction, nure gradually undergo, in presence of alkaline or contained the proportion of 7.2 grs. of nitrate of poto earthy bases ; or, still further, that they result simply ash per cubic metre. In the marl of the same deposit, from the successive accumulations of nitrates brought extracted in 1853, and which, since that time, had re- by the water employed in watering it; or, lastly, mained in a lump on the edge of the marl-pit, we ob- from these various causes united; it is still clear tained from the same volume 19 grammes of nitrate. A that their continuance in the earth depends essentially very argillaceous marl, from the hills of Chaumont, on this circumstance, that the pluvial waters do not contained 25 grammes.
carry them away. Setting aside also the favourable in. The chalk at Meudon is extracted from three overlying fluence of the temperature of humidity, everything leads workings. The limestone taken from the upper stratum, us to believe, that it is in a hothouse that a manure proin a cutting actively worked at a point where the quar- duces its maximum of beneficial effect. On this subject riers were engaged, contained per cubic metre the I may be permitted to offer some reflections. equivalent of 16 grammes of nitrate. A fact worthy of In the actual state of our knowledge it is natural to observation is, that we have found no nitre in the infe- attribute the azoteous principles of vegetables whether rior (lower) beds of chalk. When we know what is the in the form of ammonia or of nitric acids, regard being mass of calcareous matter we incorporate with the soil bad to the question of uscertaining if the azote of the in a dressing of marl, we can understand that, in spite acid does not pass into the state of ammoniac under the of the weak proportion of nitrates they contain, they influence of vegetable organism. The azote of albumen, must be sought for, since they may form part of the of casein, and of fibrine of plants, has very probably substances which are held enclosed in ihe marls in only formed part of a sal ammoniac or a nitrate. Perhaps very minute quantities, but which at the same time are
we might add to these two salts a brown matter which not less efficacious, such as phosphates of lime and al- we obtain from manure. But even with the adjunction kaline carbonates.
of this matter, still so imperfectly known, it remains an With some exceptions, we have met with saltpetre in established fact that every immediately active element of a the earths examined in sufficiently weak proportions. manure is soluble, and, consequently, that a manured soil, But we ought not to forget that the experiments have when exposed to continued rain, loses a portion more or been executed during a rainy autumn, and that the less strong, of the fertilizing agents which have been given rain tends to take away, or at least to displace the ni. to it; besides, we constantly find in drainage waters the trates. We have ascertained, in fact, that the nitre of true lixiviate of the land-nitrates and sal-ammoniacs. a cubic metre of earth from a kitchen-garden has varied And if it be true that the summits of mountains and from 316 to 13 grammes, according as they were ex- elevated table-lands have no other manure than the tracted before or after the occurrence of the rainy days. mineral substances derived from the rocks from which What is, above all, necesssary to observe in the results they are found, and the meteoric waters, it is not less obtained, is the fact of the frequency of saltpetre in 80 that in the most ordinary conditions of cultivation, a vegetable earth, whether it belongs to the forest-soil, soil strongly ameliorated yields to the pluvial waters situated at such a height above valleys, that it receives which pass through it more fertilizing principles than it as manure nothing else than the rain, or makes part of receives from it. In giving to the soil a coat of manure a tilled soil to which the most intense manuring is ap- in a slightly advanced stage of decomposition, containing plied.
by that means, rather the elements of ammoniacal proAs water tends to dissolve the nitrates, we should ducts and nitrates, than of those salts themselves, the expect to find a stronger proportion of these salts in a inconvenience resulting from the action of protracted soil moderately manured, kept sheltered from the rain. rains, is less than if they gave it rotten dung, in which I have, in point of fact, met with very remarkable quan- the soluble salts already predominate. Besides, amongst tities of salt petre in the soil of hothouses, which has the incontestable advantages arising from the application more than one analogy with artificial nitre-beds.
of liquid manures, I think we ought to place in the first In one kilogramme of earth of a botbed in the Jardin rank, that of bringing to the plants cultivated, only des Plantes, I found the proportion of 6 centigrammes matters properly modified to be absorbable, offering of nitrate of potash, or 89 grammes per cubic metre. A them to the plants only in proportion to their wants ; kilogramme of earth, taken from another hotbed in the true dressing bearing a certain resemblance to the the same establishment, has yielded the equivalent of 6 most delicate proceedings of experimental physiology, decigrammes of nitrate of potash, or 804 grammes per and which preserves the manure from the dissolvent accubic metre. *
tion of the rain waters. Our learned contemporary, M. Moquin Tandon, hav
If the meteoric-waters over which the agriculturist has ing readily authorized me to take from the hothouse of
no command, produce often an effect unfavourable to his the botanic garden of the College of Medicine the sam
cultivation, by their abundance and, above all, their unples wbich I required, I have been enabled to detect, in
seasonable intervention, it is not thus with spring and 1 kilogramme of the light black mould from the surface river waters, brought by irrigation ; or those which are of the frame, the equivalent of 0.121 grammes of nitrate held by absorption in a valley in a suitable state of of potash, or 161 grammes per cubic metre.
moisture. These waters, when we measure them to the In one kilogramme of strong earth, taken at the depth soil, yield to it the entire of the useful substances they of 30 centimetres below the light mould, we obtained hold in solution or in suspension ; calcareous and alkathe equivalent of 0.107 grammes of nitrate of potash, or
line salts, carbonic acid, organic matters, &c., and in 185 grammes per cubic metre. It will not, perhaps, be
order to show in what large proportion these dissolved * These earths had not the same density ; but I report from or attracted substances are introduced, I shall recapitumemory the weight of the litre of each earth examined. late that in a series of experiments which I had under
taken in order to determine the volume of water neces. equivalent of 18 grammes of nitrate of potash per cubic sary to irrigation in our climate during summer, I was metre. able easily to produce an absorption per hectare on land At low water the Seine delivers at Paris per second strongly seeded with trefoil, ninety-seven cubic metres 75 cubic metres, and during the average waters 250 cubic of water every twenty-four hours. This was, after all, metres. In adopting 9 grammes for the nitrate, we find not more than a watering to the extent of 9.07t. of that at low water, in 24 hours, the stream carries to the liquid per square metre. It was casting upon the soil sea the equivalent of 58,000 kilos. of nitrate of potash, a covering of water of less than 0.01 in, thickness. and the medium waters 194,000 kilos,
Amongst the salts useful to vegetation conveyed by ir- If, now, we consider that the volume of waters of the rigation to the soil, we ought to distinguish the nitrates, Seine is far inferior to that of the generality of the large the fertilizing effects of which had not escaped the saga- streams which furrow the different continents, we shall city of M. Henri Sainte-Claire Deville in the classic comprehend how immense is the mass of saltpetre conwork he has published on the composition of potable tinually borne away to the hydrographic basins ; and waters, and from wbich he has deduced as a consequence, with what incessant activity the phenomena which deterthat the waters of springs and rivers are for meadows a mine the nitritication must act on the surface of the powerful manure by the silica and alkalies they bring globe. and by the organic substances and nitrates, in which Water of Wells. I have generally found more nithe plants find the azote indispensable to their organiza- trates in wells sunk in villages and rural workings than tion.*
in springs and rivers ; but here again the proportions It is not necessary to insist upon the interest that have been most variable. For example, the water from might be attached in detecting in the waters so active a the well of Bechelbronn, which indeed is not exempt manure as saltpetre; the results at which I have arrived, from some traces of oil of petrolium, contains only indiby showing to what an extent the proportion of that cations of nitrates; whilst the water of the wells of element varies, justify besides the opportunity of exe. Woerth and Freischwiller (Lower Rhine), sunt in the cuting similar researches.
lias marl, exhibit from 69 to 94 grammes per cubic Thus I have scarcely been able to ascertain the nitrates metre, But it is in the wells of the great cities that we in those enormous masses of water contained in the find the largest quantities of nitrate. This fact has long mountain lakes of the Vosges,
since been known, and M. Henri Sainte-Claire Deville The water of the Seven Lake with the same valley, a has found in water raised at Besançon the equivalent of little below Lake Stern, and from whence flows the 198 grammes of nitrate of potash per cubic metre. The Doller, has yielded per litre the equivalent of .07m. of proportion of nitre that I have met with, in the waters nitrate of potash.
proceeding from 40 wells selected in the twelve arronThe pond at Soultzbach, near Woorth (Lower Rhine), dissements of Paris, is still larger. The experiments have formed by the dam of the little river of Soultzbach, is been executed by two processes which I have employed surrounded with mountains of sandstone of the Vosges. comparatively--the decoloration of indigo, and the inIn a litre there was but .03m, of nitrate.
genious method we owe to M. Pelouze. The well waters Spring Waters.--I have examined the waters of in which there was the least nitrate came from the folfourieen springs. The poorest in nitre were those of lowing places ; Liebfrauenberg, and of the ruins of Fleckenstein. Both
Nitrate of proceed from the sandstone of the Vosges, and the litre
Potash. contains from 0.03m. to 0.14m. of nitrate of potash,
Rue Guérin-Boisseau, in which we detected per The spring waters in which I have found the most
cubic metre the equivalent of ........ Rue Saint Martin
225 saltpetre are those of the Ebersbronn (Lower Rhine), and
Rue Sainte Georges
238 of Roppurtzwiller (Upper Rhire), which yielded re- Rue des Petites-Ecuries,
258 spectively 14 and 1l grammes of nitrate. These waters are used for irrigation.
The waters which have yielded the most nitrate were
those from the wells in the most ancient quarters. In Waters of Rivers.-Of the river waters analyzed the
the water of a well in
Rue du Fouarre, we found per cubic metre the
1,031 gr. yielded 0.07m. to 0.08m. per cubic metre.
Rue du Foin Saint-Jacques Those which contained the largest proportion of ni- Rue Saint-Landry
2,093 trate are the Veste in Champagne, and the Seine ; the Rue Traversine..
2,165 water of the former holding 12 grammes, and that of the In two wells on the grounds of market gardeners in Seine 9 grammes per cubic metre. This last result is
the Faubourgs, the cubic metre of water contained deduced from six determinations made between the 29th 1.268 k. and 1.546 k. of nitrate. It is thus seen that of November, 1856, and the 18th of January, 1857. 100 cubic metres of these waters, exclusively destined In 1846 M. H. Sainte-Claire Deville detected in the
for watering the grounds, convey to them from 120 to water of the Seine, in nitrate of soda and magnesia, the 125 kilos. of saltpetre, the utility of which as a fertilizer
cannot be disputed, especially when we know that in * Annales de Chimie et de physique, 3rd Series, v. 23, p. 52. summer a hectare of market-garden ground absorbs from The following is the summary of the labours of M. Sainte- 30 to 40 cubic metres of water per day. Claire Deville. “These analyses establish, 1st. The im- The large proportion of nitrate found in the water of portance of the portion of silica in potable waters, which M. the wells of the capital is undoubtedly due to the modiPayen had previously fouud in great quantity in the water of the wells of Grenelle. 2nd. The part which this agent, in soil is constantly impregnated are subject. The parity
fications to which the organic matters with which the connexion with the azoteong matters of the waters, takes in of the air and the water, the effects of which manifest the fertilization of meadows. 3rd. The similar part which we ought to ascribe to nitrates in the action of water as manure,
themselves so powerfully upon the public health, must and cousequently the importance of the nitrous elements in
be deeply affected with it. I have shown at another many cases. (1.) Water taken the 22nd October 1856. I men- period that the rain, after having swept, in crossing, the tion the dates, because in the waters, as in the earths, the pro
atmosphere of a large city, holds in solution or in susportion of nitrates is not at all periods the same. (2.) Water pension much more ammoniacal and putrescent organic taken the 25th October, 1856. (3.) Water taken the 24th principles than when it falls at a distance in the country. August, 1856.
To-day I have shown that the water of wells, after being
filtered through a soil similar to a nitre-bed, is tainted made arrangements for procuring the water of the Seine with substances evidently injurious. So true is it that a to the bakehouse of Scipion. This is undoubtedly an condensed population carries in itself the germs of insa- example that will be imitated ; for we cannot comprelubrity.
hend why, at Paris, they should persist in preparing At Paris, by reason of the geological medium which it bread with impure water. passes through, the water collected in the wells is not From the whole of these investigations we may justly drinkable ; nor is it drunk, or made use of in the pre- conclude that with regard to the fertilizing principles paration of food. According to that, we might suppose they bring to the earth by irrigation or absorption, the the population completely sheltered from the inconve- waters which circulate on the surface, or at a slight depth, niences which it would produce. This would be an act much more by the saltpetre than by the ammoniacs error; for it is easy to prove that every inhabitant takes which are found in them. In my paper on the ammoniacs every day the whole of the substances dissolved in a cer- of the waters I have shown that river water rarely holds tain volume of that water.
above 0.2 gr. and spring water 0.02 of alkali per cubic First, we are convinced that within the city walls metre ; now the results hitherto obtained indicate in a the lixivium (coupages) of the heavy wines and alcoholic cubic metre of the same waters the equivalent of 6 to drinks are mixed with the water of the wells ; and it is 7 gr. of nitrate of potash, answering, as azoteous manure, assorted that the bakers employ no other in making the to 1,10 gr. of ammoniac. These numbers are very bread.
nearly the same as those deduced by M. Bineau from One thousand kilogrammes of flour, in making into his chemical studies on the waters of the basin of the bread, require for the different leavens and dough 617 Rhône. litres of water.
The geological constitution of a country has likewise For produce they obtain 1,375 kilogrammes of bread, the most decided influence on the proportion of saltcontaining necessarily all the soluble substances of the petre. This influence, which is stated by M. Bineau, is 617 litres of water.
above all revealed in the course of this work. Thus, in In 1 kilo, of bread there is therefore all that is found the lakes hollowed in syenite the waters exhibited only in 45 centilitres of well water. Let us next see which traces scarcely appreciable of nitre ; those which proceed nitrates this water introduces.
from the red or quartzose sandstone of the Vosges appear The well water of the Hotel Scipion, the bakery of not to have more than 0.5 gr. per cubic metre ; whilst the hospitals, contains per litre the equivalent of 0.31 in the calcareous lands, as they belong to the trias, to gr. of nitrate of potash : this is one of the waters least the jurassique country, to the cretaceous group, or to charged with salts.
the tertiary deposits above the chalk, the spring and One kilo. of bread prepared with this water should river waters have furnished the equivalent of 15 gr. per contain 0.14 gr ; and I kilo, made with the water of cubic metre of nitrate of potash, and the proportion has the well of Rue Saint Landry contains the equivalent varied from 6 to 62 grammes. of about 1 gramme of nitrate of potash.
If in the springs and rivers there is generally more of In these weak proportions it is doubtfal whether nitrates than of ammonia, the contrary seems to exist in the nitrates are unhealthy ; but what renders their rain and snow water and dew. presence in the bread unpleasant is, that it is the indi
From experiments continued for six months in 1852, cation of organic matters, evidently proceeding from
we established that meteoric water, collected from a auspicious sources : from domestic waters for instance, or the infiltrations that escape from the 60,000 privies great distance from inhabited places, contain on an sunk below the soil. We must not forget, also, that Messrs. Lawes and Gilbert have found a number nearly
average 0.74 mgr. of ammonia per litre. Since then every year, by the rising of the Seine, the subterranean similar, by observations during a whole year, at Rotinundations put in communication the inferior with the
hamstead. upper strata of the soil, in the latter of which are the receptacles of the night-soil, &c., and that the waters in
In the summer and autumn of 1856 I have examined washing the soil convey, in what they draw, spores of ninety samples of rain collected at Liebfrauenberg. In cryptogamic vegetation-those mouldinesses always seventy-two of those waters it was possible to detect the hurtful, and so much more to be dreaded that their nitrates, which agrees with what M. Barral has stated ; organism, apparently so frail, resists nevertheless the and the quantitative results to which I have arrived, temperature of the oven in baking bread, as laid down although leaving perhaps something to wish for,
never by M. Payen, and more recently by M. Pagiale.
theless authorise me in believing that rain, when it falls In a memoir read before the Academy in 1852, I have in the middle of fields in the proximity of extensive already spoken of the disgust inspired by the well water forests, contains much less nitric acid than ammonia. when we know, and no one is now ignorant of it, that
BOUSSINGAULT, they are employed in the bakeries. Already, if I am
Member of the Academy of Sciences, and of well informed, the administration of the hospitals have
the Central Society of Agriculture.
THE ADVANTAGES OF A DAILY REGISTER OF THE RAIN-FALL THROUGHOUT
THE UNITED KINGDOM, AND THE BEST MEANS OF OBTAINING IT. That the advantages of an accurate register of the but we certainly differ from him, when he attempts rain-fall would be abstactedly useful, no one would to attach to this accurate and universal register a for a moment dispute. We would even say that for necessary action and influence over the drainage of land. certain practical purposes such, for instanee, the use It is evident that drains are not meant for a constant of water-courses as a motive-power, the regulation and never les action. Their use is to discharge of flood-gates in flat distriets exposed to inundations, water when there is an excess of water to discharge. or even for the purposes of irrigating and warping - Where much rain falls upon the surface they underlie, such an aceurate register as Mr. Denton advocates their action is more frequent than in districts where å is indispensable, if certain success be aimed at, and less quantity of water falls from above; but on account nothing left to hazardous and reckless speculation ; l of that more frequent use, provided the outlet they offer to the supply of water be sufficient, no one would capillary attraction as when falling in countries where think of laying them at closer intervals or at greater rain falls more frequently. It is true drains would be depths than in soils of a similar nature, but situated in more useful in one case than in the other ; but surely less rainy districts. The nature of the soil itself-the an accurate register, such as Mr. Denton advocates, is more or less retentive texture of its constituents—the not necessary for ascertaining that plain fact, the extopographical position and plane of the surface, are perience of the most ignorant old inhabitant of a disthe objects of much more immediate and indispensable trict being amply sufficient. In all cases where thorough considerations for the regulation of depth and intervals drainage is aimed at, drains must be laid under every than the quantity of rain that may generally fall during variety of circumstances, at such a depth and at such a whole year. A rain gauge, even assuming that the intervals that the limit of the action of one line termiinstruments now used are accurate—and Mr. Denton nates where that of the other begins, whether that action tells us that upon this important point there is a con- is to be exercised only one day in the year, or two hunAict of opinions—can only give us the quantity of rain dred days. that directly and perpendicularly falls over a plane When we say that there are districts with a rainfall area; but it does not register the quantity of water of 50 inches, and others with only 25, we do not mean which, in addition to that direct fall, flows over that every shower falls with twice the intensity upon the underlying lands from neighbouring hills, or surface one as upon the other : we only mean that rain falls twice undulations, and other causes, in which case, the regis- as often, or, in other terms, that the drains are called ter of the rain-gauge is of no earthly use. Again: it upon to act twice as often in one case as in the other; often happens, even in those districts where the rain. but to all intents and purposes the quantity of water fall is the least, that at any moment showers, such as which they must evacuate in a given time is pretty frequently accompany thunder-storms, will rush upon much the same. the land, and in a few moments pour upon its surface Then, there are other circumstances which have a a large quantity of water, which of course the drains direct influence upon drainage, which the rain-gauge must be capable of discharging.
cannot reach; and these circumstances, as regards that It is very obvious that in wet climates the drains are influence go far to compensate the difference of raivfall brought into more constant use than in drier ones. But between the western and the eastern districts of this we contend that this is the only difference, and that country-we mean the fall of snow. It is a well. difference can hardly be practically taken into account known fact that snow is a rare occurrence in Cornwall in the laying of drains; for however small the yearly and Devonshire, whereas it accumulates sometimes to average fall of rain may be, the drains may be called a great depth in the eastern counties. When that mass upon to discharge at any given moment quite as large a of snow comes to thaw, with all its accumulations quantity of water, although less frequently, as in lands against every obstacle, what becomes of the land, in situated in more rainy districts. We cannot, therefore, the spring of the year, when a high temperature and understand what practical use in drainage the accurate dryness of soil are necessary for the purposes of vegeregister of rainfall can be ; for the only local circum- tation, if, on account of the register of the rain-gauge, stances we know of, that must regulate the depth and a deviation from the general rules of drainage had intervals between the drains, is, as we have said: the been ventured upon ? It strikes us that no rain-gauge nature of the soil itself, and the topographical position of has yet been constructed so as to give anything like an the land in respect to the supply of surface water that accurate datum of the quantity of water brought down in may flow from adjacent rising grounds, to a much a fall ot snow, drifted as it generally is by a high wind. larger amount than that given by the rain-gauge, and As regards the means of effecting the general register of which that instrument cannot give the most frac- of rainfall in this country, at a cost of some £26,000, tional idea. Besides, whatever the fall of rain may be, as advocated by Mr. Denton, we are pretty confident or, in other words, however often the drains may be that no Chancellor of the Exchequer will ever be found called upon to act, this cannot interfere with the inter- to debit his budget with such an item as this, even if it vals and the depths at which the drains should be placed; were admissible that sufficiently diligent and careful for the extent of those intervals is exclusively determined individuals could be found to undertake such a task for by the nature of the soil, and should be limited only the remuneration of five pounds per annum ! by the point where the action of the drains ceases to act Apart from this anxiety of Mr. Bailey Denton to laterally—the limit of the action of one line of drains prove too much, and to overstretch the importance of ending where the action of the next line begins. the measure he advocates, his paper is replete with in.
The phenomena exhibited by the movement of liquids structive facts, and shows a great accuracy of observaare ever the same. If a shower falls over the great tion, and wonderful ingenuity in arranging the results desert of Sahara, where rain is seldom seen, its descent of his experience. His tabular records of the Hinxdownwards through the soil, sandy though it be, is re- worth drainage are certainly the best arranged we have gulated by the same opposite forces of gravitation and
THE CLEANING OF CORN FROM THE STRAW. Knocking, scutching, or rubbing out grain from now patent beaters, of different sorts, that may be said the straw, is an operation in which comparatively to perfectly extract corn from the ears without splitting little improvement is required. With a thousand or breaking it. They are adapted to damp, as well as or twelve hundred revolutions per minute almost dry stuff; and also save power, by being of a more or any “ drum"
will now beat or strip out every less wedge form, and so cleaving their way through the grain from sheaves properly opened and “ fed” to air, instead of driving it like a fan. At the Gloucester it. Much ingenuity having been applied to the shaping Meeting in 1853, and at Lincoln in 1854, about two
beaters" (some of the ndeed, being no thirds of the combined-machines thrashed clean, or improvement upon the old square ones), and to the nearly so; and about the same number
work contrivance of a better “screen, or concave,” we have without breaking the grain. At Carlisle, in 1855,
all the machines thrashed perfectly clean : two-thirds of its action on the straw. Box shakers appear to be completely avoided splitting; and two other machines, the most general favourites with machine makers. The out of the nine tested, were nearly as meritorious in original parallel-motion spars thoroughly extracted the this point.
grain and chaff by their blows underneath the straw; As regards the state of the straw, at Gloucester two- but something more resembling a riddle or screen was thirds, and at Lincoln not half the machines, delivered required to prevent straws from dropping through the straw whole; and at Carlisle only two machines lengthwise; and when boxes with wire meshes or per. were considered perfect in this respect; while four forated sheet-iron were found to catch and block up others out of the nine nearly equalled them. But with straws, or else let them through, ingenuity devised breaking the straw is a fault or an advantage, accord- slats of various forms to let through the corn, chaff, and ing to the purpose for which the straw is intended; pulse only. Then we had rocking-bars or slings at the and in districts where it cannot be sold, and is con- outer end, thus relieving us from one of the cranksumed as fodder or litter for cattle (and unless it is shafts, with all its wear and annoyances. However, if being thrashed for thatching), farmers prefer to have it you diminish the tossing action of the boxes at one end, well broken. Altogether, the performance of the you must increase it at the other, either by greater strictly thrashing part of the machines left little to be speed or a further rise and fall, or else keep the straw desired in regard to the quality of the work; and in longer upon the shakers in order to receive its due two years and a-half since that time, various improve - longing the boxes beyond the vibrating bars; but in.co
amount of blows. This latter plan is effected by proments have been introduced. The time and power requisite for thrashing a given quantity of corn varied holding back the straw, it is of course crowded closer very much in different machines; and no doubt we together than if it had free passage over, and this prinshall find a great advance in these particulars, when the cipally at the point where it most of all needs opening, dynamometer is applied, between the engines and ma- scattering, and dancing as lightly as possible—that is, chines next July.
just where the last few kernels are to be let fall out of The processes of extracting the grain free from straws, the whole mass of straw. As a compromise between ears, or chaff, delivering the clean straw by itself, and the parallel-motion, with crank-shaft at each end, and separating the chaff and pulse, colder or cavings, are
the vibrating at one end and rotating at the other, not yet conducted in the most desirable manner.
there is the plan of having half the boxes rock at one Gloucester half the machines were thought to shake
end and half rock at the other. Four boxes are the the straw perfectly clean, and one nearly so; at Lin
most common, but three have been tried, and we have coln three machines performed clean shaking, and
seen two worked with admirable effect, though of seven more out of fourteen nearly equalled them; but at
course requiring a rapid speed. But the table shakerCarlisle there were only two out of nine machines which
that is, a screen all in one piece the whole breadth of carried absolutely no grain over with their shakers,
the machine—is capable of turning out the best samples four others being only slightly defective ; while there of lung straw and cavings, as there are no apertures (as was plenty of room for improvement in the rest. So
between boxes) where straws can get down, and nothing far good, as respects the two “perfect " shakers; but
can pass except through the meshes. When cona quarter of an hour or twenty minutes' time of work- structed like a wire screen, however, straws will ening is not long enough to detect the liability of the tangle and collect in it; and, if made with slats of wood slats, screens, bars, or meshes of the shakers to collect or hoop-iron, the weight would become an obstacle to choking straws, and gradually impede the passage of its jumping movement. The peculiar motion secured corn through them; for what are at first considered by the short slings on which it swings is precisely that good shakers will sometimes be found to foul them well adapted for keeping the straw “lightened up” and selves in hour after hour of jumping underneath such loosely tossing, and as severely chucked and bounced at stuff as straw and broken cavings of all imaginable Now, cannot this be retained, and yet the shaker
one end or one part of the shaker as it is at another. lengths, bent in all possible forms, tossed in all postures, divided, so as to give a smooth and regular compenand traversing across the area of the shakers in every sating 'movement, one half rising while the other is sort of direction. is a particular, however, in which many advances have falling, and without additional slings (tiresome things) Jately been made. Another important consideration is,
or additional complication ? Suppose it made in two that this continuous clean-shaking shall be effected parts, not side by side, but one following the other, and by simple mechanism, avoiding as far as possible all
each extending the same breadth as at present. Retain shock and unsteadiness to the machine framing, and
the present slings, one pair supporting the inner end of excessive wear of brasses or working parts. Now, as
the first screen or table, and the other pair supporting the effectiveness of the process of shaking depends upon
the outer end of the second. Where the two shakers the most complete and repeated tossing or striking,
meet half-way, the first is to overlap the second, and as well as thinly distributing, or drawing out the bulk both are to be hung upon cranks or eccentrics on a of straw, so that it may give the enclosed corn and chaff shaft placed across underneath, as for driving boxevery chance of dropping out, some of the most
shakers. We should say that this arrangement would thorough shakers are objectionable in their motion;
obviate the chief objections which the table shaker is while, on the other hand, some of the smoothest and
now open to. easiest running imperfectly perform their work. How Separating corn from the chaff and cavings as they smooth and beautiful is the action of the rotary shaker, come from the thrashing machine must necessarily which dances the straw over a succession of revolving proceed on a different principle to the shaking of the rollers armed with curved rakes or teeth! Yet, simple straw in order to extract these products. Pulse, calder, as are the means by which motion is communicated to cavings, chaffings, or whatever you call the short bits these rollers, how many parts and small bearings there of straw and empty ears, can be divided from the grain are ! and the effectiveness of the work (at any rate at and chaff by screening, sisting, or straining away the Carlisle) was far from perfect. But so important is the latter through a riddle; but as pieces of straw can steadiness which it gives, the absence of shocks, and penetrate endwise through an aperture large enough to consequent smallness of wear and repairs, and freedom pass chaff and corn, the aim must be to keep them from gulling brasses and breaking shafts, that the prin- horizontal, and avoid any tossing motion that might cipiu is worthy of all attempts to increase the efficiency | turn up ears or straw into an inclined or upright posi.