62 



employed. This may be explained thus : the sketch 

 was introduced rather for the purpose of illustrating 

 certain proposed arrangements, as regards bottom heat 

 and ventilation, than as furnishing an exact and de- 

 tailed design for a model structure ; and thus it hap- 

 pened that the pipes were merely shown to be placed 

 at the front part of the house, to indicate that this was 

 their proper relative position. There would be no 

 practical difficulty in placing the pipes lower down, 

 and nearly close to the front wall, so as to admit of the 

 proposed connection ; all that would be required to 

 effect this, being to fix the slab, on which they rest 

 and which prevents the air from rushing upwards into 

 the atmosphere of the house at this point in a sloping 

 position, instead of a horizontal one. 



The principle involved in the plan proposed for 

 aeration or ventilation, is no doubt a sound one ; and 

 though the plan which is more particularly described 

 may be modified and varied, yet it is believed to be 

 efficient for its intended purpose. 



There can be no doubt that the admission of cold air 

 to a structure in which tender plants are being forced, 

 either during winter or early spring, is materially 

 hurtful to the plants, in proportion to the tenderness of 

 their constitution ; and the Cucumber being, under 

 those circumstances, a plant of a very tender and deli- 

 cate nature, is especially susceptible of harm from this 

 source. As a consequence resulting from this fact, 

 there can be little hesitation in affirming that whatever 

 fresh or external air it may be necessary to admit, 

 during the period referred to, should be warmed before 

 it reaches the plants, and in being warmed not burned, 

 but supplied with the additional moisture its increased 

 heat capacitates it to take up, and which, to be con- 

 genial to vegetation, it requires. This is provided for 



