1883.] 



AND HORTICULTURIST. 



23: 



ing question for years whether hot water or steam 

 is to be preferred for heating greenhouses. The 

 question yet remains unsettled, as is fully shown 

 by the many learned and thoroughly experienced 

 advocates of both systems who from time to time 

 give us their experience and opinions. 



I hope to again see the subject referred to in 

 your valuable columns, and trust that many of 

 those who have had the opportunity to make ex- 

 periments may give us their experience. I am fully 

 assured that hundreds of my brethren in the pro- 

 fession, as well as countless amateurs all over the 

 horticultural world, are greedy to learn more of this 

 subject. 



But what I wished to refer to more particularly 

 at this time is your remarks appended to that arti- 

 cle. 



You say "no one has answered why hot-water 

 pipes must be made to ascend. Hot water, as well 

 as cold, will travel faster going down hill." Now, 

 it strikes me that that last sentence settles the 

 much-disputed question forever, and clearly shows 

 why hot-water pipes should not be made to ascend, 

 except where unavoidable. But as the opinion 

 still prevails that they ought to ascend two, four, 

 six or more inches, according to the various theo- 

 ries, in every hundred feet from the boiler, and al- 

 though I am not prepared to prove or disprove any 

 of the theories, yet I have been constrained by my 

 interest in the subject to submit to you one or two 

 of my experiences in both systems of conducting 

 the water. 



Like the majority of my old-country brethren, as 

 well as those of this country, I have, from the time 

 I first gave the subject my attention and until quite 

 recently, been led to belive that in all hot water ar- 

 rangements the flow must have a gentle and even 

 rise from the boiler to the end of the house orturn- 

 ing point of the pipe, and a like descent from these 

 back to the boiler. In accordance with that "fixed 

 law," I have until lately laid all pipes with great 

 care, and sometimes at a great disadvantage and 

 loss, on that plan. And when I say, with great 

 care, let me add that on whatever plan the pipes 

 ■may be laid, I have always found it paid to lay 

 them with care, avoiding all unnecessary undula- 

 tions or bends, as all such, in some measure, tend 

 to obstruct the flow of the water. 



As an instance, I will briefly give an experience 

 I had over a year ago. At that time we built a 

 range of greenhouses, five in number. As the op- 

 portunity offered 1 determined to put to the test a 

 plan I had heard of and had often thought of, that 

 of laying the pipes as nearly level as possible. We 



used the ordinary 4-inch soil pipe, many of the- 

 lengths of which are a little bent, consequently the 

 entire line is slightly undulating. The main, a 

 5-inch pipe, passes along the ends of the houses, 

 under the floor level. At each side of each house 

 an offset raises the water from the main to about 

 twelve inches above that level. From that point 

 the piers or supports for the pipes were built on one 

 level, the pipes being laid on them, the flow above 

 the return, as is customary, each return bend be- 

 ing furnished with a 4-inch air-escape tube. 



All being in readiness and the fire started, a gen- 

 tle warmth was soon perceptible all along the 

 pipes in all the houses, but as the water reached a 

 higher temperature the pipes in several of the lines 

 gradually grew colder, and I immediately con- 

 cluded that there was air collected at those points 

 where the stoppages occurred. After several at- 

 tempts to overcome the difficulty, 1 at last had all 

 the pipes raised at the return ends about two inches 

 (the houses are about 55 feet long), and the air 

 immediately rushed out of the escape pipes, and 

 since then there has been no trouble from that 

 source. The experiment was enough to show me 

 that nothing was to be gained by laying the pipes 

 level, and also that there is indeed very little mo- 

 tive power in hot water, and that what little there 

 is had better be utilized to the best advantage. 



Since that time I have become a convert to what 

 we call here the "down-hill plan" of conducting 

 the water. Although very sceptical for along time, 

 I am at last convinced that it is superior to all 

 other plans. I need not here give my reasons for 

 thinking so, as should I, it would simply be to re- 

 peat what Mr. S. C. Moon has said in his able arti- 

 cle on page 75 of the Monthly. 



Although he has not said so, he undoubtedly 

 means the tanks which receives the hot water di- 

 rect from the boiler to be furnished with a tight- 

 fitting cover ; if not, I would beg leave to suggest 

 that a cover should be fitted to the tank to prevent 

 the evaporation of and loss of heat, and that for 

 the escape of air a small '4 -inch tube be inserted 

 in the cover. 



Where a cheaper arrangement may be desirable, 

 a very good substitute for the tank may be had in 

 a perpendicular 4 or 5-inch pipe, according to the 

 size of the flow. This pipe to be carried up about 

 four or five feet above the level of the top of the 

 supply tank; and, by the way, I have found in 

 practice that the more this tank is elevated above 

 the boiler, and provided the inlet to the boiler be 

 in the return pipe and, I think, better close to the 

 boiler, (a very small tube will answer the purpose) 



