60 ALPINE FLOWERS [PART I. 



fitted with a supply pipe and tap, so arranged as to be within 

 easy reach (though hidden from view), it should have an over- 

 flow and an outlet pipe fitted with another tap for completely 

 emptying the whole at will. If the bed is large, it would be 

 well to arrange for stepping-stones here and there to ensure 

 easy access to the plants. When space is limited, I often use 

 for this purpose thin flat stones raised a little and supported 

 at each end by a miniature pillar of bricks and cement, thus 

 forming a little bridge, as it were, and admitting of the space 

 between the little pillars and beneath the stones being filled 

 with the proper soil. That every trace of cement-work would 

 be hidden by soil, stones, or plants, goes without saying. One 

 advantage of this sort of bed is that the water supply and 

 drainage can be regulated in the simplest manner by the mere 

 turning of a tap. 



" TJie Partly Cemented Bog Bed. The advantage I claim for 

 this lies in the facility it affords for graduating moisture, which 

 makes it possible to grow plants requiring different degrees of 

 humidity in the same bed. First of all, a bog bed is con- 

 structed after the manner described above under the heading 

 of ' Bog Beds without Cement/ but instead of having the sides 

 more or less upright, they are kept gently sloping. A winding 

 trench is then excavated through this bed and secured with 

 cement concrete a water-tight trench not more than a foot wide 

 and 6 inches or 8 inches deep. The cemented sides should 

 be level, so that, when filled, the water would flow evenly over 

 the sides and into the outer parts of the bed, so giving different 

 degrees of moisture between the cemented centre and portions 

 and the sloping sides, from which the water would drain away 

 naturally. Before the water is admitted, the trench is filled 

 with loose stones and brickbats, and is then bridged over with 

 large pieces of peat, and covered with a few inches of suitable 

 soil. It is then levelled, so as to show no visible difference from 

 the rest of the bed. As soon as the trench is filled with water, 

 however, the latter will rise by capillary attraction not only 

 through the pieces of peat, but also the soil above it, showing 

 even on the surface of the soil the course of the water-trench 



