A few days since we saw at a friend's a contrivance which we think admirably adapted to supplying heat temporarily to a cold pit, and it may be used by the gardener under a variety of circumstances where a constant supply of heat is not needed. Our friend, unfortunately, is subject to attacks of that abominable complaint, the rheumatism; having experienced relief from the application of bottles of warm water, and finding the bottles unhandy, be had made several earthenware jugs resembling in shape horse-shoe draining tile, the , bottom being slightly concave, so us to fit nicely to the leg; on the top is a neck for supplying the hot water: if too warm, the temperature is moderated by wrapping the bottle in flannel. Now bottles of this kind, some two or three feet long, we conceive to be well adapted to cold pits, etc, when danger is apprehended from sadden and extreme changes in the weather; and these often occur. A couple of these bottles placed in a small pit, with the usual covering on the sash, would set Jack Frost at defiance. Iudeed, we do not see why, with the aid of several such bottles of suitable size, a good many plants could not be kept in a growing condition during the whole winter, and furnish a good supply of flowers.

A small under-ground greenhouse might thus be heated at a trifling expense, and be made available for something more than the mere protection of half-hardy plants. Camellias, Roses, Geraniums, etc, would thrive well under such circumstances. In severe weather the bottles would need to be filled night and morning, but the sashes should always be kept uncovered during the day. The intelligent gardener will perceive a number of circumstances under which these bottles can be made very useful, and we hope he will give them a trial. Any potter can make them. To the amateur we would especially commend them for the purposes above named. They are not patented, and the readers of the Horticulturist can use them for the " rheumatics" or the pit at their pleasure.

W. T. C.'s communication has been received, and we have something on the other side; but at present we do not wish to open the "grape" question. At the proper time both sides can be heard. It is true that some still continue to plant the Isabella and Catawba mainly, and it is equally true that others, who have grown these extensively, are working their old plants with kinds which they conceive to be better. It is not denied by any, we believe, that the Isabella and Catawba are fine grapes; but the question is, are they the standard of perfection, and are we to be content with them, and cease striving after anything better? We think not. But we drop the matter for the present, simply reiterating the opinion heretofore expressed in the Horticulturist, that we already have better grapes.

We are not fairly in the traces yet, but when we get well harnessed we expect to go ahead at a lively gait. We think we could pull better with a good "pile" of subscribers on our hack; at all events we should like to see it tried, and now is the time to do it. Will our friends take the hint?

Our Agents in San Francisco, Cal., are Warren & Carpenter. Mr. J. Q. A. Warren, having formed a partnership with Mr. Carpenter, under the title of Warren & Carpenter, has removed from his former place of business to 167 Clay street, where they have constantly on hand the latest news and literary matter, received regularly by steamer.

The Horticulturist may be found at their office, and we commend them to our friends in that part of the country.