436 



PITS AND FRAMES 



being carried on pillars of brickwork a ; 

 and in the divisions between these pillars 

 are pipes or tubes of common earthen- 

 Fig. 603. 



Ill III ill! 



1 It II 11 II 11 II 



1 » 1 II 1 II II II 1 II 1 1 1 II II II 1 IN II 1 



i ii i ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii i ii i 







-w 





ware, c c c, 

 may be rm 

 be require 



■ IOOOO 



4 inches in diameter, which 

 ide larger or smaller, as may 

 i, and on the top of the pipes 



Fig. 604. 



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000 ! 



on (Mill iwi noil ouoni 



I place a small garden-pot d, when it is 

 necessary to alter the soil : this prevents 

 the admission of earth into the pipes. I 

 find that the introduction of these pipes 

 causes a considerable increase of heat, 

 and when I uncover the frames now 

 (March) in the morning, the thermome- 

 ter stands always at 80°, the variations of 

 heat being very slight. The brickwork 

 behind all the pipes should be made open 

 at the end joints for the first four or five 

 courses. I would have made the openings 

 in the brickwork much larger than shown, 

 had it not been that I am troubled with 

 rats. The circles b on the ground-plan 

 are sea-kale pots, 18 inches in diameter at 

 bottom, and 9 inches at top, which stand 

 upon open brickwork, as shown by the 

 section ; the whole of the bottom part of 

 the frame, to the height shown on the 

 section, being filled with open brickwork 

 for the admission of heat." 



Glendinning 's pine pit, fig. 605. — This 



pit was erected at Bicton by Mr Glendin- 

 ning some years ago, and has been found 

 to answer the purpose intended. The 



following description of it is taken from 

 his excellent work, " Practical Hints on 

 the Culture of the Pine- Apple a 

 spaces for the linings of dung and leaves; 

 b b boards hung with hinges to cover the 

 linings ; c c barrel-drains ; d d d d grat- 

 ings with communications conveying the 

 drainage and rain water to the barrel- 

 drains c c; e e wood plugs, to take out 

 and admit steam from the linings; // 

 level of the surface of the ground." 



Forsyth's early forcing pit, fig. 606. — 

 In the eleventh volume of " The Garden- 

 _ Fig. 606. 





— b 



- — , 



I 





f \ 



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3 c 





e 



1 Ilk b m a 





r 



ers' Magazine," Mr Forsyth has published 

 the annexed pit with the following de- 

 scription : " a a show the stone copings of 

 the walls ; b b cast-iron pipes, 4 inches in 

 diameter and 6 feet apart, connecting the 

 steam flues ; c c cavities in the brick- 

 work through which the hot air and steam 

 pass from the linings into the steam flues ; 

 d cast-iron pipes, 3 inches in diameter, 

 conducting the water from the gutter 

 into the drain, tending also to strengthen 

 the front wall and support the coping, by 

 being placed under every third rafter ; 

 e e tile covers to the steam flues, with 

 brass plugs like those used in wooden 

 water-troughs, 2 feet apart ; / ground- 

 level ; g coping of the front wall, which 

 serves also as a gutter. This groove or 

 gutter need not be large, as the column 

 of water cannot be great collected from a 

 light and a half, the receivers being placed 

 under every third rafter. The cast-iron 

 pipes introduced here to connect the 

 steam flues are intended also to support 

 planks 3 inches thick, closely fitted to- 

 gether, which are to be used in summer 

 as a walking way, and to hide the then 

 almost useless lining pits ; " but Mr For- 

 syth would by no means use them in 

 winter, "as it would prove injurious, by 

 causing the condensed steam to drip upon 

 the linings, thereby rendering it too wet 

 for proper fermentation; besides, the 

 linings in winter ought to be made up as 



