GLASS HOUSES. 123 



houses, and the north countryman will see the seasons actually 

 rolled ten degrees backward in his favour, for Angers is just 

 about ten degrees loM'er in latitude than Aberdeen. 



Mr. Rivers is a nurseryman by trade and for profit, and a 

 fruit-grower in his orchard houses only for pleasure ; he is, 

 moreover, located in one of the finest situations in England, as 

 regards climate, being on the flinty gravel of Hertfordsliire, just 

 above the Essex swamps, sheltered from the breezes that sweep 

 over higher ground, and sufficiently inland to be defended from 

 those off the water. The latitude of Hertfordshire is about 

 midway between Angers and Aberdeen ; the reader will, there- 

 fore, see what can be done in lat. 52^ at Sawbridgeworth, and 

 thus arrive at the principles which guided Mr. Rivers in con- 

 tending against certain difficulties of climate. I may add, from 

 my own experience of Hertfordshire, that I have never found any 

 locality in England so well suited for the higher order of horti- 

 culture, being generally sunny above — that is, free from fogs — 

 and on the gravelly knolls the soil, though poor, is unquestion- 

 ably healthy and dry. 



But although Mr. Rivers has only had to glaze the earth in 

 sunny Hertford to equal Angers 5^ further south, I must state 

 from my own experience of Aberdeen that another element must 

 be added to the orchard-house to adapt it to the Straths of Don, 

 5° northward of Hertford, and 10° on the frosty side of Angers, 

 where the open hedge would be a very ineffectual barrier to a 

 snow-drift. 



It is, therefore, evident that sound principles of construction 

 in glass house building are safer guides in general practice than 

 trusting implicitly to these experiments in favoured localities, 

 however honourably and faithfully detailed. In the valley of 

 the Thames, at Syon, the amount of hours of sunshine during 

 winter was thirty per cent, less than those registered at East 

 Barnet, in Herts, only 15 miles distant, but out of the London 

 fogs and far above the level of the Thames. 



The principles that guided Mr. Paxton in glass house building 

 may be gathered from his own published accounts, and it will 

 enable strangers to form a correct judgment when I state the 

 nature of the climate that he had to contend with. The climate 

 of that part of the valley of the Derwent where Chatsworth 

 stands is one of the worst in England. The kitchen-garden, 

 where the finer plants are kept, is very little above the bed of 

 the river; and the climate is so uncertain that I have known the 

 dahlias at Chatsworth to be killed by frost in August. Although 

 the latitude is only one parallel northward of Herts, tlie climate 

 is of such ungenial quality that only a few miles (if "'^re than 

 one) from Baslow the land is not worth cultivation. And as 



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