General Notices. 315 



verses over two drains, the one placed at the back and the other at the front. 

 These fire bars traverse at the rate of about 6 ft. per hour, and onl}' require 

 a power about one thirtieth of a horse to keep them in motion. The fuel being 

 introduced on the bars at the entrance, through a hopper, is carried onwards 

 by the traversing motion of the bars, passing through all the relative stages 

 of combustion until nothing but the scoria or unvolatilisable portions remain, 

 which are rejected at the back. It will be seen that in this arrangement, when 

 the fuel is first introduced, it parts with its more volatile portions, which are 

 consumed with the fuel farther advanced on the bars, and consequently in a 

 more perfect state of combustion. By this process all the carbon is burnt, 

 instead of being distributed in the atmosphere, which is at once seen by 

 the total absence of smoke in the chimneys of the furnaces where it is em- 

 ployed. This is of itself a great saving in the economy of fuel ; but another 

 equally important is in the fact, that the coal dust or refuse coal answers 

 all the purposes of the largest and best coal. Through the constant admis- 

 sion of atmospheric air between the fire bars, the heat of the furnace is con- 

 stant and uniform, and there is no clinkering of the bars, which come out of 

 the fire as clean in the evening as they did when tiiey entered in the morn- 

 ing. The hopper, which supplies the fuel, may be made to contain a supply of 

 fuel for an unlimited time ; and thus the regulation of the fire is rendered 

 quite independent of the caprice or neglect of the stoker. 



This furnace appears to be interesting to the gardener in two ways : 1st, 

 because the general adoption of some such arrangement, where the important 

 object of effecting the combustion of smoke is accomplished, would tend 

 greatly to improve the purity of tlie atmosphere, and prove beneficial to the 

 cultivator ; and, 2d, as it might be economically and advantageously employed 

 in heating houses upon a large scale, particularly with the hot-water appa- 

 ratus. — A. B. 



The Tree-Creeper (^Cerlhia familidns) and the Green Fly that infests GerU' 

 niums. — Once upon a time one of the little birds called tree-creepers entered 

 a small greenhouse, and took up its abode therein for a day and a night, at 

 the end of which time it had cleared the plants of insects most completely. 

 Not a leaf nor a twig escaped its searching glance. As its scientific name im- 

 plies, it was quite tame and familiar, and never seemed to heed the intrusion 

 of strangers, but still continued to carry on its work of destruction. But, 

 alas ! on the second morning the voracious little bird was found lying stiff 

 and cold in the corner which it had fixed on for its bed, having, in fact, 

 glutted itself to death. Gardeners, if you wish your greenhouse plants to be 

 free of insects, encourage the Certhia familiaris when you have it, and try 

 to procure it when you have it not. — A. S. M, Braes of Goivrie. 



Wireiuorm destroyed by the Mole. — A singular instance of the utility of 

 protecting the mole has within these last ievf days come under my observa- 

 tion. Having had occasion to turf up a number of small clumps in our 

 flower-garden, I was astonished in a iew days to find that the moles had 

 pushed up the turf over the whole surface of some of the clumps. I imme- 

 diately searched for the cause of their visit to these patched up clumps ; 

 when, to my astonishment, I found the wireworm in great abundance between 

 the surface of the former clump and the new-laid turf. They had, I suspect, 

 been in the turf before it was laid down, and, the ground beneath being beat 

 so hard, they could not penetrate farther; where the moles, having once 

 discovered them, seemed determined on eradicating them. They were mostly 

 the larva of Agriotis lineatus, with a few of A. obscura. What was very sin- 

 gular in this instance is, that before this time I never saw a single indication 

 of a mole in the garden, although there were plenty of them in the wood which 

 surrounds it. — John Dunlop. Worcester Bark Gardens, near Kingston, 

 May 10. 1843. 



L'ylisus Addm'i, Furple Labnrnmn. — I write to communicate to you a further 

 freak of this singular plant. The tree of my brother, Mr. Algernon Herbert, 

 at Ickleton, near Saffron Walden, having for some 3'ears ripened seed on 

 both the yellow-flowering branch and the small-leaved purple-flowering 



