i88i.] NOTES FROM THE PAPERS. 219 



NOTES FROM THE PAPERS. 



'' HoTWATER-MEN," as gardeners term " Horticultural Engineers," do 

 not always know most about heating ; and as to boilers, one has only 

 to contemplate some of their misshapen and thoroughly stupid inven- 

 tions to understand how much they know about their business ; but 

 they are not quite so bad as some "judges" of boilers. There are men 

 who have had a large share in awarding valuable prizes to stupid boilers, 

 who possessed no real knowledge of the subject whatever. There are 

 numbers of common-sense people who have never yet fathomed the mys- 

 tery of awarding a grand medal to a boiler because it was a common 

 "saddle" squeezed in at the sides to make these perpendicular (a bad 

 fault), and had its inside capacity reduced in order to make two chimneys 

 under the roof of it. Fancy erecting a fireplace in a room with the 

 half of the grate or heating portion of the fire turned to the wall ! 

 AVhat we wish particularly to refer to here, however, is the paper read 

 lately by Mr A. D. Makenzie of Edinburgh on " Economy in Fuel " in 

 garden furnaces. Mr Makenzie's ideas are sound, and simple as welJ. 

 He prefers a boiler with plenty of internal capacity for fuel, and with 

 a grate-bar wide enough to admit sufficient air to burn it thoroughly. 

 Any inventor may proceed on these lines. It is not that portion of 

 real mamifactured heat going up the chimney, and supposed by some 

 to be lost, which troubles the Edinburgh engineer so much, but the 

 heat that escapes in a latent state — i.e., in the form of smoke and un- 

 burned particles : he wants to burn the " reek," which is just what 

 some of our fine boilers will not do. They are tar-distilling and gas- 

 making apparatus. ^Yhen the stoker feels his hoe getting sticky with 

 tar as he pushes it under his " water jacket" boilers that boast of " no 

 fire-brick settings" or other aids to perfect combustion, he may then 

 always be sure that his coal is going away bodily up the chimney, or 

 being expended to worse purposes. Listen to what an eminent 

 authority says on this point : " If a fireplace were required to be 

 constructed so as to drive off as much as possible of the hydrogen in 

 an unignited state (that is, to merely waste the fuel), the best plan 

 would be to have the furnace bars and sides formed of pipes with cold 

 water constantly circulating through them. Those portions of fresh 

 coal which lie against the boiler undergo for some time distillation 

 rather than combustion ; and while they are thus ivasting they inter- 

 cept a large portion of the boiler surface from the central portion of 

 the fuel, which is probably in a state of incandescence." . If your 

 readers will apply this test to some of our " double million power," 

 hollow-barred heating apparatus of the present time, it will give them 

 a more accurate conception of their merits. Very wisely, too, does Mr 

 Makenzie tell us that he prefers a long low boiler to a short lofty one, 

 for he has found that with a short boiler he could not raise the same 

 heat as with a long one. Plenty of stokers know this from experience. 



