20 On the Cultivation of Lettuce. 



number another of our London correspondents will have 

 more to say relative to these boilers, and the iron Tanks of 

 Messrs. Burbidge & Healy. 



The following is Mr. Glendenning's description of the pit : 



a An arch in the back wall, in order to allow of the setting of the boiler. 



b Boiler. 



c Smoke flue carried through the back wall into a chimney in a high wall at the end 



of the pit. 

 d Cast iron gutters for the circulation of hot water in the chamber. 

 e Stop cocks for the puroose of shutting off the water so that one division of the pit 



can be worked without the other. 

 f Hot water pipes for the purpose of warming the atmosphere of the frame, as shown 



in the Section at p. 18. 

 g Cast iron gutters for hot water as shown in the plan d. 

 h Hot water pipes as shown in plan/", 

 i Flue from the boiler to the chimney. 

 k Soil in which the plants are grown. 



/ Slate covering the heated chamber in which the soil is placed. 

 m Ground level, the pit being sunk about two feet. 



Art. IV. On the Cultivation of Lettuce, so as to produce 

 successive crops the year through. By J. W, Russell, 

 Newton, Mass. 



As lettuce is more or less used in every family, the mode 

 of obtaining it in the greatest perfection, throughout the year, 

 in regular succession, may not be unacceptable to a portion 

 of your readers. 



Lettuce is grown in considerable quantities for the market, 

 and fine heads may be obtained nearly the winter through ; 

 in the months of December and January, owing to our severe 

 weather, it cannot be grown as large as it can in the climate 

 of England, without too much care and expense ; but later, 

 when hot-beds do not suffer from extreme frost, it may be 

 had in the greatest perfection. Notwithstanding lettuce may 

 be found in the market of such excellence, few individuals, 

 except market gardeners, understand its cultivation during 

 the winter, and on this account many gentlemen are deprived 

 of this desirable vegetable during that season, when it adds 

 so much to the luxury of the table. 



