136 GARDENING FOR BEGINNERS 



considerable. The heating apparatus consists of a large sliding tank for 

 the oil and one or more burners. A sufficient quantity of oil is stored 

 to burn from sixteen to twenty hours, thus avoiding soiled hands and 

 unpleasant work late in the evening. Of course the lamp requires regular 

 and careful trimming, a remark that applies with equal force to an ordi- 

 nary table-lamp. Even a table-lamp of the duplex kind will protect the 

 plants in a small house from danger during a sharp frost. The different 

 forms of hot- water apparatus heated by oil are perfectly free from smoke 

 and smell, provided always that the lamp is thoroughly trimmed. It is 

 portable, therefore can be readily shifted to that part of the structure 

 requiring the greatest amount of heat. As the lamps require no 

 chimneys, flues, or fixtures of any kind, and the dirt and inconvenience 

 of stoking are entirely obviated, the different forms of oil stoves may 

 be recommended to the amateur. A little experience will determine 

 the best position for the stove, which should not be closer to the 

 plants than can be helped, consistent with being in the best position 

 for heating the greenhouse. 



As with proper attention the lamps are quite clean and free from 

 smell, these oil stoves can be used where the greenhouse or conservatory 

 is attached to the house, with a communication between the two. They 

 are not in the least unsightly ; indeed, some of the better forms are 

 quite ornamental. When heating a greenhouse too high a temperature 

 must not be maintained during winter. The object is simply to keep the 

 plants free from frost and not to unduly excite them, for those that ex- 

 perience a period of comparative rest during the winter grow with greater 

 freedom than those which have been placed under warmer conditions 

 at the dull period of the year. For an average greenhouse, with the 

 usual occupants of such a structure, a night temperature of 45 degrees 

 is quite sufficient; indeed, it may during very severe weather drop 

 another 5 degrees without injury. Even in the depth of winter 

 artificial heat may be frequently dispensed with for days together ; but 

 after a spell of wet, dull weather, even when no frost is likely to occur, 

 it is sometimes advisable to light the stove for a short time to dry up 

 superfluous moisture. 



Many forms of propagating cases for seeds and cuttings are heated 

 with an oil lamp; but an objection to these is that they give off too 

 much heat, hence the young plants quickly become debilitated, and are 

 not so strong as those raised in the ordinary atmosphere of the green- 

 house. 



Potting Soils. The preparation of soils for potting is important, 

 and often sadly neglected. It is a common practice to dig up a little 

 garden soil for this purpose, the result being unhealthy plants, and 

 general disappointment. 



The potting composts, which are blended in various ways according 

 to the requirements of the plants, are technically known as loam, peat, 

 leaf-mould, decayed manure, sand, and cocoanut fibre refuse. 



Of these the most important is 



Loam, as it forms the principal portion of the compost for nearly 

 all classes of plants. It is really the common earth of the fields and 



