THE PINE-APPLE. 29 



all round them for the heat to escape. After the heat sub- 

 sides, the tan can be pressed to the sides of the pots again. 

 Of course, when bottom-heat is derived from hot water, 

 it can be easily regulated without these precautionary- 

 measures, which apply onl}' to fermenting materials. 



The temperature should now be carefully regulated, 

 and fire-heat applied in the evening just in time to pre- 

 vent the heat from sinking below 70° at ] p.m. And 

 when the morning gives signs of a bright day, the fires 

 should be damped down the first thing, and kept low all 

 day. There is nothing more injurious than to have hot 

 pipes, and a bright sun, with a maximum supply of air 

 on. Such a state of things creates currents of scorching 

 dry air, very trying to the plants, and robs the pineries 

 too much of moisture. By the middle of May the 

 plants will be growing freely, and moisture and air must 

 be increased in proportion to the progress they make. 

 The house should be damped the first thing in the morn- 

 ing as well as at shutting-up time. And after being shut 

 up close for four or five hours, when the weather is 

 calm and very warm, a little " chink " of air should be 

 left on all night. A little more air should be put on at 

 7 A.M., and gradually increased with the rising of the 

 sun, till at twelve o'clock there is sufficient to create a cir- 

 culation among the plants. Air should be given at the 

 back or highest part of the house or pit ; but, unless when 

 the weather is close and sultry, none should be given at 

 the front. With the increase of heat, light, and air, they 

 will make rapid progress, and consequently more water 

 at the root will be required, and it should always be 

 about the same temperature as the bottom-heat. I 

 have found Peruvian guano the best and most con- 

 venient stimulant for mixing with the water — not 



