MISCELLANEOUS INTELLIGENCE. 67 



ANSWERS. 



On Heating by Hot Water in Glass Tubes, 1836, p. '2Ij. — R". must 

 be ncler some mistake respecting glass tubes, employed in hot water appearance 

 as is statement that thev give out heat quicker, and retain it longer is self-con- 

 tradictory, to say nothing about the affording a higher temperature. The sub- 

 ject was most accurately investigated by Mr. T. Tredgold, some years ago. 'Die 

 result was, that water in a glass tube gives off its heat rather more slowly than 

 in an iron one — in the ratio of 155, 180, where the iron is covered with rust, as 

 hot water pipes generally are — consequently iron pipes give out heat quicker, and 

 under equal areas of external surface, produce a higher temperature than glass 

 would, and ot course the heat contained in them is more rapidly expended. 

 With respect to glass tubes, the difficulty and expense of joining them, would 

 probably prove an insuperable objection to their use, if their brittleness were not 



a sufficient one. 



I 



On the Heat of a Furnace, &c.j 1S:}6, p. 137.— I see a Correspondent 

 at Canterbury, is incredulous as to the time whichfthe little furnace mentioned in 

 page 46, continues to burn. The fact, however, was as stated, and since that 

 time, another furnace smaller than the former, as having rather less diameter 

 and conical, has remained alight without any attention an equal time. When- 

 ever it is filled with fuel and regulated, it burns untouched, twelve hours, 

 and only requires stirring up to put it to work in the morning. It must, how- 

 ever, be observed, that the combustion for a great part of this time is so slow as 

 to produce very little heat. 



On Growing Cape Bulbs in the Open Ground, page 1836, p. 137. — 

 may be glad to be informed, that notwithstanding all that is said about growing 

 Cape Bulbs in the open ground, those who attempt generally lose their plants, or 

 if they succeed, the dowers are so indifferent as ill to reward the trouble. A few 

 strong species succeed, but the wet of our autumns destroys most kinds, and the 

 frosts cut up those which sur.vive. If he will try, he must drain his beds well, 

 raise them high, and protect them from all rain after October begins. 



C. B. B. 



REMARKS. 



A List of Fifty excellent Sorts of Dahlias. — I forward you the 

 requested list of Fifty Dahlias, together with a few others which are spoken of 

 in the highest manner, but not having seen them, I have omitted them in my 

 list ; those to come out this season, and which T have placed amongst the fifty, 

 I have seen, and can highly recommend. Quilled Perfection must be considered 

 a first-rate flower, and Sir H. Fletcher, Dodds's Mary, and Jones's Sulphuria 

 Elegans, unequalled. I speak thus favourably of the latter, from the bloom 

 exhibited at Salt Hill last year, which was splendid. Addison must also be in 

 every collection, and will, I think, find itself a place in every good stand of 

 blooms. I should remind growers that this is Granta's year, it having been 

 rally remarked that this splendid flower is in perfection only every other 



On Spotted Leaves of OrchidEjE. — A Correspondent in one of your late. 

 numbers, complains of spots in the leaves of his Orchidese, which do not appear 

 to be caused by insects. As 1 have found that cold, especially during the night, 

 when there is moisture on the leaves, affects many tender stove plants in the 

 way he describes. I think it is possible his Orchidea? have suffered from that 

 cause — a temperature much below 65 degrees, especially during summer, when 

 the heat by day is great, will generally cause spots. C.B.B. 



To Destroy Slugs, Woodi.ke. Earwigs, ,.\.c. — Take some cabbage leaves, 

 and either put them in a warm oven, or hold them before a fire, until they are 

 soft, then rub them with salted butter, or any kind of fresh dripping, and lay 

 in the places infested. Jacobus. 



