1873.] COWAN'S SYSTEM OF HEATING. 507 



time, the flower-buds are actually thrown off altogether, and the crops are 

 thus lost. In the northern parts of England and Scotland, where there 

 are less chances of thorough ripening, late Peach-cases should have 

 some means of being artificially warmed, in order to ripen the wood in 

 such autumns as 1872, and of this year also, when we have had such 

 sunless and wet seasons. It does not matter how healthy the trees 

 may be ; no power at the command of the gardener can insure a crop 

 if the buds and wood are not, to say the least, moderately well ripened. 

 We saw several houses near the very centre of England where strong- 

 growing Peach-trees had not produced any fruit, and from no other 

 cause than that of the want of applying, or having the power to apply, 

 fire-heat to ripen the wood and " plump up " the buds. And after the 

 very sunless and wet season we have this year experienced over a 

 great breadth of the kingdom, if like results follow, employers should 

 not blame their gardeners unless it be where they have the means of 

 firing the trees in autumn and have neglected to do so. Peach- 

 cases should all be heated, to enable gardeners to cope with the effects 

 of a dull season in the case of the Peach crop, as well as render such 

 structures available for wintering half-hardy plants, in many cases 

 where such accommodation is of the worst description. 



COWAIST'S SYSTEM OF HEATING HOTHOUSES OW THE 

 COMPENSATING SYSTEM. 



The Editor has previously described the principles of this system in the 

 * Gardener' (see p. 245), and I now allude to the question after having seen 

 the system at work on the 4th inst., under peculiar disadvantages, on the 

 Marquis of Salisbury's estate at Hatfield. Mr Bennet, who now has 

 the extensive and increasing gardening establishment under his charge, 

 had resolved to adopt this system on principles of economy, and invited 

 a party of gentlemen interested in Horticulture to visit the apparatus 

 on its being started into work. The result of the trial was as success- 

 ful as could be expected, although this at Hatfield partook somewhat 

 of the nature of an experiment, owing to chalk being used along with 

 the anthracite coal instead of limestone, which latter Mr Cowan finds 

 the best for his purpose. This is the first time chalk has been em- 

 ployed with Cowan's apparatus, and we must compliment the inventor 

 on the satisfactory result obtained. The kiln at Hatfield is about 12 

 feet wide, and from 12 to 14 feet high, the interior being egg-shaped, 

 and containing a solid mass of fuel 10 feet high by 6 feet in diameter 

 in the centre or widest part. Over this glowing mass of chalk and 

 coal an improved saddle-boiler, designed by Mr Cowan, and manu- 

 factured by Messrs Hartley & Sugden of Halifax, is placed. The 



