528 General Notices. 



hitherto made public of heating by hot water, in circulating the fluid in open 

 gutters instead of pipes. Hence, it can only be applied in cases where the 

 gutters can be conducted on a level ; but the water may be easily carried over 

 a door, on the siphon principle, or under it, on the principle of water always 

 finding its level. The advantages of this mode, Mr. Corbett says, are cheap- 

 ness, simplicity, and efficiency. Cheapness, because iron gutters are cheaper 

 than iron pipes ; simplicity, because water running in open gutters has less of 

 mystery about it than water concealed in pipes ; and efficiency, because it 

 produces a moister heat than any other mode. We should have thought it 

 would produce too moist a heat for many purposes, particularly in the 

 autumn ; but Mr. Corbett says that this is not the case. " There never can 

 be a superabundance of moisture, provided the gutters are of the proper shape; 

 but, should it be considered advisable at any time to prevent the escape of 

 vapour altogether, this may at once be effected by placing along the top of the 

 gutter any flat substance, such as slates, tin plate, &c. : the water never being 

 in a boihng state, the vapour is not forced out, but will condense on any sub- 

 stance with which it comes into contact. For forcing vines, pines, &c., it is 

 admirably adapted ; and, with broader and shallower gutters, to produce more 

 moisture, there is reason to conclude that this system will come into general 

 use for the cultivation of cucumbers, melons, &c. For hot-house plants, and 

 particularly Orchidese, gutters as broad or even broader than deep, are pro\'^ed 

 to be the most suitable. For the green-house it will be of incalculable service. 

 Every description of artificial heat without moisture has been found by sad 

 experience to injure green-house plants, when hard weather has compelled its 

 introduction. To many, and particularly to Cape heaths, it is almost certain 

 death ; because the air in frosty weather, containing, perhaps, not one grain 

 of moisture per cubic foot, and raised by fire heat to 40°, and sometimes even 

 higher, becomes so intensely dry and oppressive, and acquires such an affinity 

 for moisture, even at this low temperature, that the rapid absorption while 

 the plants are in a dormant state causes their juices to be elaborated too 

 quickly for their powers of secretion." 



Not content with recommending his mode as the best of all modes for 

 heating houses in which plants are grown, Mr. Corbett makes a long quota- 

 tion from Dr. Ure's article published in the Trmisactiotis of the Royal Society, 

 and, with some variations, in the Architectural Magazine, vol. iv. p. 161., on 

 the effects of dry air on the officers engaged on duty in the long room of the 

 Custom-House, London ; and he arrives at the following conclusion : — 



" It is evident, then, that the great desideratum for heating apartments, &c., 

 is, an apparatus capable of circulating, in any direction, and to any extent re- 

 quired, any quantity of artificial heat without the malaria of the stove and 

 pipes, so as to maintain a genial warmth and wholesome ventilation through- 

 out the building. Such a system is now placed before the pubhc, capable of 

 such modifications as to become every way suited to effect these desirable 

 objects ; equally adapted to horticultural purposes generally, and to public 

 buildings, offices, and domestic apartments ; calculated alike to maintain the 

 healthy and vigorous tone of the animal as well as the vegetable economy ; 

 and on a principle whose operations are more assimilated to Nature's own 

 atmosphere than any other method hitherto discovered." 



It is quite right that this mode of heating plant-houses should, like every 

 other, have a fair trial ; but the idea of heating apartments to be occupied by 

 human beings, with hot water in open troughs, is too palpably absurd to deserve 

 a moment's consideration. Others, however, entertain a different opinion on 

 this subject from what we do. At a meeting of the Plymouth Horticultural 

 Society, held July 19., the Rev. C. T. Collings in the chair, " a neat model of 

 Mr. Corbett's Hygrothermanic apparatus, for heating hot-houses, &c., was 

 exhibited ; an invention which the late president of the Plymouth Horticul- 

 tural Society, Thomas Woollcombe, Esq., says ' will do more for the advance- 

 ment of horticulture, than anything which has been produced for the last cen- 

 tury.' The peculiar characteristic of this invention (for which the Plymouth 



