THE GREENHOUSE AND CONSERVATORY 135 



the brightest part of the day from the middle of March onwards. 

 Flowering subjects last much longer thus treated, but permanent shad- 

 ing should not be put on before April. 



So many horticultural builders now make a specialty of greenhouses 

 for the amateur that even if it be intended to put up the structure one's 

 self the most satisfactory way will be to obtain the materials from a 

 trustworthy firm, and supplied ready for putting together. After the 

 house is put up two or three good coats of paint both inside and out 

 should be given, as these preserve the wood. 



Heating. During the greater part of the year artificial heat is un- 

 necessary for the greenhouse ; it is required more or less throughout 

 the late autumn, winter, and early spring months. Various devices 

 have been employed to keep the structure at a given temperature during 

 frosty weather, but the usual way is to have a boiler outside to heat a 

 certain quantity of hot-water pipes within the greenhouses. Several 

 prominent manufacturers have devoted much attention to the produc- 

 tion of a boiler that needs little attention and will burn for many hours, 

 with the result that some most effective boilers can now be obtained. 

 The quantity of pipes necessary to protect from frost and their arrange- 

 ment depend so much upon the situation of the structure and many 

 other items that the most satisfactory way is, after having selected the 

 form of boiler, to ask the maker's advice. Of course all particulars 

 must be supplied, as in this way only a correct opinion can be formed. 

 In the case of boilers of all kinds much depends upon the way they are 

 managed. Cleanliness is an important item, and this applies not only 

 to the boiler itself, but to the flues connected with it. In frosty weather 

 the most critical time is usually about daybreak, hence the boiler should 

 if possible be attended to then, and if it has remained untouched through 

 the night it will contain little fire. This must be freed from ashes and 

 clinkers, when it burns freely, and soon causes the water to circulate 

 briskly in the hot-water pipes at that important moment. Care should 

 be taken, however, not to make the pipes too hot, as they then give off 

 an enervating dry heat injurious to plants, though it encourages the 

 insects that prey upon them. Such being the case it is better to spread 

 the heat over more pipes than to keep those in use too hot. Whether 

 coal or coke is used it should be broken small and slightly damped, as it 

 will then last longer and give greater heat. Attention to these minor 

 details makes the successful stoker. In the case of an amateur with a 

 small greenhouse two great objections to the above-named systems of 

 heating are : firstly, the expense ; and secondly, the fact that stoking, 

 even if carefully done, is dirty work, and irritating late in the evening, 

 when during frost the fire must be attended to. This has led to a great 

 increase in the use of 



Oil Lamps for keeping out the frost, and the firm of Eippingille, so 

 noted for their oil stoves of all kinds, have brought out some good forms 

 for heating greenhouses. Though varying in power the principle remains 

 the same ; it is that of an upright boiler, connected by means of hot- 

 water pipes with a standard of the same height as the boiler. This 

 allows a free circulation of water, and of course the heat given off is 



