THE DUTCH FLUE. 



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The economy of fuel is a matter of so much importance, that Tvhat- 

 ever plan can be demised for lessening its consumption, must be received 

 as a national benefit. ^luch has been written, and, Tve fear, to little 

 purpose, on the economy of fuel when applied to domestic purposes. 

 Much less has been written, and much more effected by practical ex- 

 perience in the economy of this article, when apphed to horticultuTal 

 purposes ; and in all probability-, the perfection of the principle of heat- 

 ing has been attained by the inyention and apphcation of the hot water 

 system. 



In endeavouring to lay down mles for regidating the temperature of 

 greenhouses, plant stoves, &c., it will sufficiently appear that the same 

 rules are equally appMcable to forcing houses, pits, and structures of 

 every denomination. To render our ^iews on this subject as clear as 

 possible, we shall give a brief detail of the various modes practised, 

 pointing out, as we proceed, the merits or defects of each. 'V^'e adopt 

 tliis arrangement because hot houses are erected under such a variety 

 of ckcumstances, that some one of the various modes detailed, may, 

 in some cases, be found more convenient and practicable than others. 



The Dutch, to whom we are indebted for our first hints on the 

 apphcation of fii'e heat as a mediimi for warming hot houses, employed 

 earthenware or can flues at fii"st, and, in many cases, these are employed 

 to the present day. These consisted of pipes, similar to those used for 

 conveying water, but of lai'ger dimensions, being seldom less than from 

 nine to twelve inches in diameter, they were joined together with 

 cement, and sometimes placed upon bricks, to keep them cleai' of the 

 borders, at other times they were embedded in sand, vdih the view 

 of retaining the heat longer in the house. The advantages of these 

 flues are, that they can be rapidly heated, and, therefore, may be used 

 with advantage in greenhouses and pits where moderate fii'cs are used, 

 and where the intention is to repel sudden attacks of frost ; but they 

 requu'e unusual attention, as they are quickly heated, and cool with 

 equal rapidity. These flues were formerly much used in this coimtr}-, 

 but have long since given place to brick ones, as being more safe and 

 steady in their operation. 



The next improvement in heating, originated also with the Dutch, 

 and consisted of broad and deep fines ; the former is still used very 

 generally in Holland and Geimany, and the latter is almost in universal 

 use in Hussia. These, also, were adopted in this coimtry, but have in 

 their tiu'n long ago given place to other forms. 



The most primitive mode in use in this countiy, however, was to build 



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