2133. The art of heating by hot water, which is now most generally practised in hothouses, was invented in Paris in 1777, by M. Bonnemain; and it was first made publicly known in this country by Count Chabannes, in 1815. The first hothouse heated by hot water appears to have been one at Sundridge Park, Kent, which was heated by Count Chabannes, in 1816. In 1818, a pamphlet was published by this gentleman, in which he describes what he calls a 'new water calorifere,' and its application to various purposes in domestic economy and horticulture. Notwithstanding the undoubted fact, that both a dwelling-house and a hothouse were heated by hot water in this country by Count Chabannes as early as 1816, the invention is claimed by Mr. Anthony Bacon, and Mr. Atkinson; though it appears that neither of these gentlemen began their experiments till 1822, six years after the 'water calorifere' had been exhibited to the British public. We have no doubt, however, that the idea was, to a certain extent, if not altogether, original, both on the part of Mr. Bacon and Mr. Atkinson; because neither of these gentlemen seem to have been at all aware of what had been either done or written by Bonnemain or by Count Chabannes. Mr. Bacon stated, that he took the idea of heating hothouses by hot water, from having seen, above eighteen years previously to 1822, a leg of mutton boiled in a horse pail. The breech of a gun barrel was put in the fire, and, the muzzle being inserted in the side of the pail near the bottom, the water in the pail was made to boil, and kept boiling. Mr. Atkinson is said to have been led to think it would answer to heat forcing-houses with hot water, from an experiment which he had seen made by the late Count Rumford, about the year 1799. Whatever may be said respecting the invention, nothing can be more certain than that Mr. Atkinson was the first who successfully applied this mode of heating to hothouses.