AN ENCYCLOPEDIA OF HORTICULTURE. 



119 



Heating* continued. 



warmed; an additional amount of purity in the air being 

 claimed by the inventor in consequence of this process. 

 The Syphon Condensing Stove is considered useful and 

 available for small lean-to or other houses, containing a 

 cubic capacity of from 600ft. to 800ft., in places inacces- 

 sible to a hot-water apparatus. 



FIG. 181. MINERAL OIL STOVE, WITH DOUBLE BURNERS. 



Mineral oil stoves (see Fig. 181) are perforce used by 

 amateurs for excluding frost from small houses in winter. 

 They are objectionable on account of the strong smell 

 caused by the oil when burning, but are useful where no 

 other means of Heating can be procured, or as a sub- 

 stitute at times when a permanent apparatus gets out 

 of order. Large oil stoves with double burners emit a 

 considerable amount of heat, and materially raise the 

 temperature in a small house. 



All boilers should be provided with a tap near the 

 bottom, for emptying, in case of repairs, or for removing 

 sediment that collects inside. Air taps must be fixed in 

 the highest points of the flow pipes, or, better still, a small 

 lead tube may be connected and carried up the inside of 

 the house, higher than the level of any part of the 

 apparatus. Hot- water pipes are usually made of cast iron, 

 and the joints may be connected with various compositions, 

 such as cement, red and white lead mixed, steel filings, &c. 

 Each substance is largely used by different Heating 

 engineers, the last-named being perhaps the oldest, and 

 when mixed with the proper proportion of sal-ammoniac, 

 and a little sulphur, to cause rusting the most sub- 

 stantial method ; it is, however, more difficult to dis- 

 connect joints made with this preparation than when red 

 lead is employed. Strong hemp packing, in addition, will 

 be requisite in either case. Some persons prefer joints 

 made with flanges, and screwed together, with vulcanised 

 indiarubber washers between. These occupy more space 



Keating' continued. 



than ordinary sockets, but have the advantage of being 

 easily replaced. Indiarubber rings also make good joints, 

 and are quickly renewed or removed in cases of neces- 

 sity. They are made of the proper size, and placed on 

 the smaller end of one pipe, which is then pushed into 

 the socket end of the other. All pipes in use should rest 

 on firm walls or stands prepared for them ; sufficient room 

 for expansion being allowed on each side, and at the ends. 

 To insure a free circulation, the interior must be kept 

 free from air, and all valves should be capable of open- 

 ing a waterway as nearly as possible the full size of 

 the pipe. A water cistern must be provided, and fixed 

 at a higher level than any part of the apparatus it 

 has to keep supplied. 



HEBECLADUS (from hele, pubescence, and Hados, 

 a branch ; in reference to the hairiness of the young 

 shoots). OBD. Solanacece. A genus containing about five 

 species of stove perennial herbs or sub-shrubs, natives of 

 Western tropical America. They thrive in a rich sandy 

 loam and leaf mould. Propagated by cuttings, made 

 from half-ripened wood, and inserted in sand, under a 

 bell glass, in bottom heat. 



H. biflorns (two-flowered). fl., peduncles axillary, solitary, 

 forked or trifid, bearing two (rarely three) handsome drooping 

 flowers ; calyx glabrous, with five spreading segments ; corolla 

 of two colours, lin. or more long ; tube conico-cyhndrical, purple, 

 hairy, striated ; limb of five spreading, green, narrow-lanceolate 

 .segments ; stamens much exserted ; anthers blue-purple. August. 

 I., lower ones solitary, alternate; upper ones in unequal pairs, 

 sub-ovate, shortly petiolate, acute. Branches more or less 

 spreading, terete, glabrous. Andes of Peru, 1844. Sub-shrub. 

 (B. M. 4192.) 



H. ventricosus (ventricose). fl. one or two together, on short 

 drooping peduncles from the axils of the leaves ; calyx finely 

 pubescent, toothed ; corolla pale yellow, Jin. broad and deep ; 

 limb toothed. Summer, fr. a large, glabrous, poisonous berry. 

 I. shortly stalked, ovate, acute, entire, or slightly sinuate- 

 dentate ; upper surface bright medium green ; the lower paler. 

 h. 3ft. to 4ft. Peru. Shrub. (Ref. B. 208.) 



HEBECLINIUM. See Eupatorium. 

 HEBENSTRETIA (named in honour of John Ernest 

 Hebenstreit, 1703-1757, Professor of Botany in the Uni- 

 versity of Leipsio). OED. Selaginece. A genus contain- 

 ing about twenty species of greenhouse evergreen shrubs, 

 sub-shrubs, or annual herbs, natives of South Africa 

 (one extending to Abyssinia), few of which are seen in 

 cultivation. Flowers white or yellow, sessile; spikes 

 terminal, often dense, short or elongated. Leaves alter- 

 nate or scattered. The species thrive in a compost of 

 sandy fibry loam, with the addition of a little peat. 

 Propagated by cuttings, made of short young shoots, and 

 inserted in sandy peat, under a bell glass, in spring. 

 H. dentata is increased by seed. 



H. dentata (toothed), fl. white; spikes smooth. May to 

 September. 1. linear, toothed. A. 1ft. 1739. Annual. (B. M. 

 &) 



H. fruticosa (shrubby), fl. white, in oblong spikes, disagreeably 

 scented at night ; calyx small, bipartite ; corolla tube longer than 

 calyx, filiform ; bracts entire, ovate, acuminate, sometimes ciliate. 

 August. 1. linear-lanceolate, dentate or rather pinnatifid-dentate, 

 smooth when full grown ; young ones somewhat hairy along the 

 midrib on the under side. Stems shrubby, h. lift. 1816. 

 (B. M. 1970.) 



H. integrifolia (entire-leaved), fl. white. May and June. L 

 linear, quite entire, h. 1ft. 1792. (A. B. R. 252.) 

 HECHTIA (named after J. H. G. Hecht, a Prussian 

 Counsellor, who died in 1837). OBD. Bromeliaceas. A 

 genus containing about six species of pretty greenhouse 

 herbs. Flowers small, disposed in a compound spike. 

 Leaves long, spiny, crowded, recurved, subulate, linear. 

 For culture, see Tillandsia. 



H. argentea (silvery).* fl. white, small, in globose clusters. I. 

 in a dense rosette, sharply recurved, rigid, IJft. to 2ft. long. 

 General habit of II. Ghiesbrephtii, but very distinct by reason of 

 the dense silvery coating of both leaf surfaces. Mexico. 

 H. cordylinoides (Cordyline-like). /. numerous, small, in a 

 much-branched panicle. I. lanceolate, recurved, remotely and 

 strongly saw-toothed. Mexico, 1881. Habit tufted. (B. M. 

 6554.) 



