Improving a Lawn liable to be burnt up in Summer by Drought. - Above twenty years ago, the lawn in front of a house at B -was more or less burnt up every summer, in consequence of the sandy nature of the soil and subsoil. We recommended taking out the subsoil to the depth of 1 ft. all over the lawn, retaining the surface soil, and mixing it with loam from a meadow at no great distance, by repeated trenchings. These trenchings were performed without intermission, during dry weather; and, we believe, above a dozen men were employed for three weeks in trenching this lawn over three times. Had we the same work to perform again, instead of manual labour we should apply Finlayson's harrow or Kirkwood's grabber, either of which implements would do the work better, and incomparably quicker. To get the work done quickly is a very great advantage; because by that means it may be completed while the weather is dry, and every one who has had any experience in mixing soils on a large scale, knows, that to do this properly in wet weather, or partly in wet and partly in dry weather, is impossible. The conditions are, that the two soils to be mixed should be in the same state of minute division, and of dryness; and that the soil to be added should first be evenly spread over the other. For want of attending to these conditions, farmers sometimes lay lime on land in such a manner that it can do little or no good; viz. when the lime is wet and the land dry, or the contrary; or when both lime and land are wet. To mix soils equally and thoroughly, and in such a way that the mixture may remain mixed, both soils ought to be as nearly as possible in a state of dry powder. Even when sand and loam, or lime and loam, are mixed in this state, owing to the different specific gravities of sand and loam, and of loum and lime, there will be a constant tendency in the mixture to separate, by the milking of the heavier soil or earth, when the mass is moist, as explained in Vol. XIV. p. 96. Hence, all soils that are mixed artificially require to be superintended by art (SO to speak) for many years afterwards, in order that they may at proper intervals of time be ploughed up or trenched, so as to remix the heavier soil with the lighter. In the case of a lawn treated as we have described in dry weather, if, immediately after mixing, the soil be rolled hard while yet dry, having been previously (if necessary) properly underdrained and sown down, it will scarcely require remixing in a lifetime; but in the case of grass lands badly drained, or from any cause liable to be soaked with water, remixing will become necessary, probably in twenty or thirty years, according to the difference of the specific gravity between the original soil and the soil which is added. Any one may prove this, as suggested in Vol. XIV. p. 97., by filling two pots of earth with soil of the same quality, placing at the bottom of one pot a layer of stable dung, and at the top of the other a thin layer of lime. After a greater or less number of years, according to the quantity of rain that has fallen on the pots, the stratum of dung will be found at the top in the form of black vegetable mould, and the stratum of lime at the bottom tinged with yellow. The completion of this experiment may be accelerated by artificial watering, so as to exhibit the effects described within a year. In the lawn to which we allude, the soil being dry, and with a good declivity, we found, after twenty years, the mixture nearly as homogeneous as when it was nowly made; and on June 14th, though the weather had been warm and dry for some weeks previously, the grass was of a dark green, forming a striking contrast with the grass of an adjoining field, across a sunk fence, where the soil had never been mixed. We are convinced, from this instance, as well as from general reasoning, that all the dry grass lands in the country might be greatly improved by this mode of treatment; and, in many cases, so as to pay the expenses during a fifty years' lease. At all events, it would well repay, both in effect and in produce of grass, the proprietors of parks. With respect to lawns, and, indeed, kitchen-gardens, on sandy soils, it is evident that to render such soils as productive, and as retentive of moisture, as loams, must be one of the greatest improvements that can be made in them. Some may consider the plan we recommend too expensive, or, in other words, it may require more money than they can afford to lay out; but, in the case of small suburban residences, where the most is to made of every thing, no money could be better expended. Indeed, on a large scale, say in the case of an estate of from a hundred to a thousand acres of poor sand, with loam or clay at no great distance, we should think the money laid out would at least pay as well as money laid out in the purchase of land. It is less expensive to improve sand by adding clay, than to improve clay by adding sand; because, in the latter case, the subsoil requires to be drained, and this can only be done effectually by the frequent-drain system. For example, it would be much easier to prevent the grass on the sandy parts of Hyde Park from being burnt up in hot weather, than it would to render the clayey loam of the Regent's Park so firm by sanding and draining, as not to be poached by cattle in wet weather.