The Fruit and Kitchen Gardens, near Paris. 61 



to be more effective, with less fuel, than was required for the 

 hot water. This mode certainly deserves to be made the sub- 

 ject of experiment, in order to ascertain exactly its advanta- 

 ges, so as to be able to state them in numerical terms. In the 

 first place, it will be necessary to take into consideration the 

 expense of ojie cast iron pipe, of six inches diameter, compared 

 with two four-inch pipes, flow and return, for hot water. The 

 circumference of the six-inch pipe, is to the sum of the cir- 

 cumferences of the four-inch pipes, as 18-857 to 25-142, or 

 within a fraction of 15 to 20. It therefore appears, that about 

 one-fourth less metal is required for the flue, than for the 

 pipes ; and if it were possible to get the larger casting, at the 

 same rate per lb., as the smaller, the cast iron flue would be, 

 in the first instance, a saving of 25/. per cent. This alone is 

 an important object; and when the saving of fuel and more 

 eflective heating are stated to be the results, certainly no 

 more arguments need be adduced in favor of the plan. It is 

 necessary, however, to make a few remarks with reference to 

 the position of the cast iron flue. It was stated above, that 

 it uniformly ascends along the front. This being the case, 

 the heated air also ascends naturally towards the farther end, 

 thereby causing a less pressure in that part of the pipe next 

 the fire. This part would become excessively hot, if the pipe 

 were level, and would even give out a greater excess of heat 

 next the fire, than the old flues, iron being a more rapid con- 

 ductor than the materials of which they were composed. 

 Probably one foot in twenty would be a suflicient gradient ; 

 those observed, appeared to rise more than this." 



The Montreuil mode of training peach trees, and the Tho- 

 mery plan of training grapes, are noticed at length, with illus- 

 trative engravings, but, as our article has already extended to 

 considerable length, we shall refer to these at another time. 



Mr. Thompson left Paris, March 18th. by railway to Rou- 

 en, and arrived in London on the evening of the 20th. In 

 concluding his notes, he acknowleges the kindness he experi- 

 enced in France, from every one engaged in Horticulture, to 

 whom he had occasion to apply for information. He found 

 all intelligent and obliging, anxious to avail themselves of im- 

 provements in Horticulture, and willing to communicate a 

 knowledge of their modes of cultivation to others. 



