The most hypothetical element of this calculation is the width assigned to the base of the mountain; but by the very nature of the question, it has but little influence on the final result; since, by even doubling the assigned diameter, the total attraction would not be altered a twentieth. In regard to the mean density of the mountain, if it were taken at 2.75, instead of 2.66, that of the earth would result 4.94, instead of 4.77, as given above. E. S. _Transactions of the Horticultural Society_. Vol. vii. Part 1. 4to. London, 1827. pp. 208. I. _Observations upon the Growth of Early and Late Grapes under Glass_. By Mr. James Acon. Few gardens are to be found in which bunches of fresh ripe grapes can be gathered every day in the year: notwithstanding the importance of the fruit to the luxurious, and the facility with which the vine submits to the artificial climate of the forcing-house. Nothing is easier than to secure crops of grapes in a vinery during the spring and summer months; but it is far more difficult to obtain them in the last and earliest seasons of the year, when the plants would [p160] naturally be in state of torpidity. It is well known that this desirable purpose is attained in great perfection in the garden of the Earl of Surrey, at Worksop Manor; and the management there practised is the subject of this paper. The common methods of forcing early grapes are to train the vines under the roof near the glass, or on small frames against flued walls; but to both these practices Mr. Acon finds great objections: to the former because it renders the house too dark, and exposes the young and tender branches to the pernicious effect of blasts of cold air rushing through the interstices of the panes; and to the latter, because the heat of the flues is apt to scorch the branches, and in consequence to destroy the crop,—excessive heat in the one case producing the same injurious effects as excessive cold in the other. The following are the two modes by which Mr. Acon obtains his _very early_ and his _very late_ grapes. For the early crops a house is used, of which the back wall is 9.6 feet in height, and the front wall 3 feet, the roof forming an angle of about 30 degrees. It is heated, from the absolute necessity of employing an atmosphere of unusually high temperature, with two flues that pass along the middle of the house, and return in the back wall; a fire-place being built at each end of the house. Forcing begins on the first of September, and the fruit begins to ripen the first week in March. The vines are trained upon a trellis, fixed over the flues, in the centre of the house, and also upon the back wall; but none are allowed to obstruct the light by occupying the roof, until about six weeks after the forcing has commenced, when some new shoots are introduced and trained to the rafters. The form of this house gives it a peculiar advantage, in presenting a greater surface for the growth of vines