350 



JOUENAL OF HOETICtJLTURE AND COTTAGE GAEDENESi 



{ Way 4, 1876. 



fulcrum of heat. I do not see how thia is to be altered unless 

 we give heat by day by a lower set of pipes, and at night by a 

 set of roof pipfs. 



It is, however, against the placing of the pipes along the 

 sides of ppans and the fronts of lean-to that I wish to offer 

 some remarks, and shall the better perhaps explain myself by 

 a section showing resnlts. Fig. 99 is a section of a vinery 

 intendwd to have the Grapes ripe at the close of April or early 

 part of May, and is heated by four rows of 4-ineh pipes fa), which 

 — as the house is only narrow, 12 feet — is snfScient to maintain 

 a suitable temperature for Vines in their several stages, as 

 indicated by a thermometer suspended at h ; but in severe 

 weather, and there is usually plenty of it between November 

 and May, the pipes have to be kept at a high temperature — the 

 water as hot as it can be just clear of boiling. The Tines are 

 a mixed lot — White Frontignau (the most certain of all Grapes 

 for early work), Backland Sweetwater, Black Hamburgh, Mill 

 Hill Hamburgh, Black Muscat of Alexandria, and Muscat of 

 Alexandria. These Vines break well and regularly, but differ 

 as to time. The first eyes to start are between c and d, followed 

 by those between d and c ; the latest between c and /', and are 

 strongest in shoot and fullest iu bearing between c and d, per- 

 ceptibly weaker in growth and in number of bunches, and size 

 both in bunch and berry, whilst at the upper part from e to / 

 the break and shoots are weak, the bunches are few and small, 

 or conspicuous by their absence. Then in setting it is all that 

 could be desired, even with Muscats, from c to d, lefg good 

 from d to e, and certainly no better set is experienced from 

 f to/. These remarks as to setting apply 

 only to Muscats ; all the others set well 

 the whole length of the rafter. There is 

 also considerable diffrrence in the ripen- 

 ing. From c to d the Grapes are lipa 

 when those between d and e are colour- 

 ing, and between c and / there is a dif- 

 ference in ripening of fully three week?. 



Now, if the h^at be the cause of thia 

 discrepancy in breaking, in btrength of 

 shoot, in Eetting, in quantity and quality 

 of fruit, and in ripeninj", the principle of 

 having all the heating surface in front is 

 wrong, as it certainly is diametrically op- < 

 posed to the transmission and radiation V 

 of natural heat, it being equal in trans- 

 mission, in refraction, and radiation, as 

 we know full well that without depressing 

 the Vines in a house started in or after 

 March we have a result in breaking, in 

 vigour, and in produce in inverse order 

 to that above stated. The placing of 

 the pipes at the sides or fronts of houses 

 appears Uke what Mr. Pearson once said 

 of walls — seeking warmth at a bonfire — 

 one side roasted and the other cold, 

 which, applied to the case in hand, would 

 mean the Vines from c lod would soonest 

 feel the effects of the artificial heat, it would be considerably 

 lessened in temperature from d to c, and less again from c to/, 

 whilst the moisture would be greater in d to c, and more abun- 

 dant still in c to/, but the most moisture would be found in 

 the mass of cold air, or rather the moisture atcending in the 

 heated air would be condensed by the glass in part, by the 

 back wall, and be present most in the atmosphere beneath the 

 dotted lines from the heated surfaces to d, e, and /. The 

 temperature must also be more equable at the lower part of 

 the house, for by giving air by the top ventilator (,7) the heated 

 air is let out, and cold will rush in by the same orifice to 

 supply the vacuum cautei by the air-giving. 



To avoid a recurrence of the evils above alluded to, ventila- 

 tion by the front or side lights has been suggested, and in more 

 than one instance adopted. It is well known that by admitting 

 top air we let out the heated air more quickly — lower the 

 temperature more rapidly than were ventilation admitted by 

 the front or sides, the upper ventilators being closed. This 

 new principle of air-giving is certainly of a date that would in 

 this age be entitled to be termed old, for I can remember 

 pineries and vineries with very ineflicient upper ventilation, 

 all the front or side lights being made to open by the slide-past 

 system, these beiog very much more resorted to than the 

 cumbrous top-sliding lights. In admitting air by the front or 

 side lights in the first instance it is certain we make the most 

 of the artificial heat, the object being to admit fresh air with- 



out diminishing the temperature, and make the most of the 

 solar heat by retaining it instead of letting it escape by the 

 opening of the upper ventilators, or only to let pass an excess 

 of temperature beyond which it would not be safe to allow the 

 temperature to rise. This side ventilation I take as proof of 

 the wrong disposal of the heating surfaces, and cannot but 

 look upon the admission of air in unheated houees, or those 

 moderately aided by artificial heat, as other than that the top 

 ventilation, whilst it allows the escape of heated air, permits of 

 a rush in of cold. The former defect may be remedied by an 

 equal distribution of the heating surfaces instead of concentrat- 

 ing them along the sides and fronts, and the other so that the 

 cold air may not be by a raised light as 17, be forced in at the 

 rate at which it travels, but by a more equal distribution of the 

 means of ventilation — the cold air passing over the openings, 



Fig. 99. 



or by a lantern light so as to blow through. In most cases the 

 necessity for front or side ventilition vanishes as assuredly 

 will heated air by every opening it can pass, but more rapidly 

 by upper than side ventilation. 



To return to the section, fig. 99. It appears under-heated; 

 the pipes in cold weather have to be maintained at the highest 

 point practicable in hot-water heating. Add two more pipes, 

 h and i, and the result will be different. Of course, but it is 

 only adding heat where we have already too much, the neces- 

 sity for front ventilation being made more imperatively need- 

 ful to subdue its drying influence on the Vines between c and d. 

 I do not question that by front ventilation the atmosphere 

 would be so modified as to give r and / an advantage equal 

 to c and d ; but I take exception to having the pipes at one 

 side or both sides, and consider the six pipes disposed as 

 shown in (,./', /.-, /, m, and », would give a more equable tem- 

 perature and attendant moisture, the necessity for front ven- 

 tilation before top would be void, and the recourse to the 

 remedy of a defect made necessary by wrong disposal of the 

 heating surface would not cause us to commit another almost 

 as bad, for such in my opinion is the admission of side air 

 before upper. It is wrong in principle, and that which neces- 

 sitates it must be wrong also. 



This departure from the orthodox system of placing the 

 pipes over each other, the flow being the upper, and the lower 

 the return, is, I am glad to say, now being very generally 



