Conical Boiler for heating Hot-houses. 129 



About the middle of April last, Mr. Penn had twenty large pine 

 plants from out of my houses, a number of which were queens; 

 and it is universally acknowledged that at this season of the 

 year the queen pine is of little value, in size, appearance, or 

 flavour, rarely seen to swell the pips prominently, or to come of a 

 good colour. The result of Mr. Penn's principle, in this instance, 

 has fully confirmed my opinion that forcing is a farce without it. 

 My pines, in the same pit from which Mr. Penn had his plants 

 in April last, are now ripening, and some cut, swelled, as they 

 usually are, to about a pound and a half each, and with a flavour 

 little better than a Swedish turnip. Those at Mr. Penn's (one 

 of which you and I partook of yesterday) possessed every pro- 

 perty of a queen pine. It was well swelled, of a most beautiful 

 colour; and its flavour was equal to any queen pine ripened in 

 August. Mr. Penn's pretensions to horticulture are certainly 

 very limited. He knows but little about forcing ; the gardener 

 that grew the plants, less. Such being the case, it can only be 

 the system which has produced such an effect on the size and 

 flavour of the pine. This system, I am happy to say, has far 

 exceeded my most sanguine expectation, and as it must be seen, 

 fully to appreciate its value, I shall be happy to exhibit it in 

 action to the horticultural world about April next, when I shall 

 invite all friends to horticulture to see it at work in my extensive 

 forcing establishment. — Isleworth^ Feb. 6. 1 840. 



P.S. The man that grew the pine plants having lately left Mr. 

 Penn, I cannot accuse his present gardener of want of ability. 



Art. XI. On the Conical Boiler for heating Hot-houses by hot Water. 

 By D. Beaton. 



If the reader will turn to the 13th volume of this Magazine, at 

 page 298., he will find drawings and descriptions of the original 

 conical boiler, which was invented in 1835, at New York, in the 

 United States, by a lad only 18 years of age. This useful in- 

 vention, which is destined to make an entire revolution in the 

 system of heating by hot water, created little interest at that 

 time in Britain, and might have passed down the current of ob- 

 livion like the mere bubble of a season, had it not been for the 

 ingenuity and perseverance of J. Rogers, Esq., F.H.S., Vine 

 Cottage, Sevenoaks, Kent. Under this gentleman's directions 

 it was greatly improved by Mr. Shewin, ironmonger, of the same 

 place. The credit of bringing this boiler prominently before the 

 British public is therefore due to Mr. Rogers.* He presented 



* Since Mr. Beaton sent us this article he has supplied us with the follow- 

 ing note. " I have since learned that, as far as Mr. Rogers is concerned, it 



