420 THE GARDENER. [Sept. 



middle level, are the most satisfactory, requiring little trouble in the 

 management of valves, and are all that we could desire with some- 

 what slow fires ; but beyond the valves in the mains mentioned above, 

 which by the way, are always open, we have a house 86 feet long, and 

 a ran°-e 150 feet long, divided into three compartments. The pipes 

 in the first of these, beginning at the end nearest the boilers, cannot 

 be heated to the same temperature as the houses immediately below 

 them The second compartment is cooler still; and to show the differ- 

 ence between the first and third, we may say that during last winter, 

 when the heat in the former was above 40°, the frost was in the latter, 

 which is the highest point to which the water flows from the boilers, 

 and to which it has a direct, straight, and uninterrupted run. We 

 may add that all our houses are well supplied with pipes, having been 

 put up for forcing Pines and Cucumbers. 



The position of affairs stated above is exceedingly annoying. If we 

 increase our fires in order to obtain the required heat in the highest 

 houses those on the lowest levels are literally roasting. Surely there 

 must be something theoretically wrong here. Either the engineering 

 skill brought to bear in their arrangement was sorely deficient, or there 

 are exceptionable cases in nature's irresistible laws ; for we are unfor- 

 tunately in possession of an instance in which hot water persistently 

 refuses to run freely up-hill according to the rules and regulations laid 

 down by the most scientific hot- water engineers, and we do not think 

 any amount of figures or elaborate calculations would have much effect 

 in inducing the water to alter its ways. 



Joseph Hamilton & Son. 



Wellington Place, Carlisle. 



In the May issue I suggested that it would be well, if the discussion 

 on heating by hot-water continued, to provide ' The Gardener ' with a 

 safety-valve ; and I hoped Mr Makenzie would have supplied one on 

 the " strata " principle. As yet he has not done so ; neither has he, in 

 his last paper, alluded to a stratum of any kind, hot, cold, or of average 

 temperature ; and I begin to fear that the " strata" theory of circula- 

 tion has exploded, and that of average temperature sunk to zero. 



I am glad, however, judging from the length of his last paper, to 

 observe that he has not suffered any bodily injury through the occur- 

 rence, and the strata valve may yet take a place as an auxiliary in the 

 mercurial barometrical chimney-pump theory of circulation, as pro- 

 pounded by him in ' The Gardener ' for August. 



I do not think the average-temperature point worth warming up 

 again ; but I know Mr Makenzie will pardon me if I again ask him, 

 Does the upper and hotter stratum travel faster than the under and 

 colder stratum on the down-hill journey % and if not, why not 1 



Mr Makenzie says he has refuted my statements, and that I am 

 " wrong fundamently on almost every point." I have no doubt he 



