184 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



rji.NE> 



carried the pillar out through the ceiling and roof of the room. The 

 fire-grate and flue thus enclosed, had a chimney-piece of slate set to 

 correspond. The slate, not being so good a conductor of heat as iron, 

 does not give out any thing like the same quantity of heat an iron 

 pillar or pipe would have done; at the same time tlie lieated air, 



Eassing U|) through the slate pillar imparts to it such a degree of 

 eat, as adds very perceptibly, and I may add very pleasantly, to the 

 warmth of the room. The Welch slate, as is well known, will crack* 

 on being exposed to a very slight degree of heat, but my slabs were 

 made ol Valencia slate (from quarries in Ireland), which do stand heat 

 very well, if cautiously applied in the first instance. 



The superficial quantity of slate used was very small, the slabs 

 being veiy narrow, consequently the expense was very trifling. The 

 economy of heat I consider to be no small advantage in ray plan. In 

 the case of a common brick chimney let into the wall, the heated air 

 passes up it, imparting no heat to the room, but in the case of this 

 slate pillar, erected mithin the room, the heated air passing up through 

 it, is conducted by means of the slate into the room. Indeed it was 

 found that the warmth of the room was fully maintained with a very 

 small consumption of fuel. 



Should you deem this little plan worthy of being brought to the 

 notice of your architectural friends through the medium of your 

 valuable Journal, it will much oblige. Sir, 



Your obedient humble servant, 

 London, May 6. A Lover of the Fireside. 



ALARUM WHISTLE FOR STEAM BOILERS. 



Sir— The enclosed sketch represents, in section, a simplified form 

 of alarum whistle for steam boilers which has occurred to me. Should 

 you deem it worthy of insertion, you will perhaps give it a place in 

 your valuable pages. 



a, i, k, h, is a float, which consists of an inverted vessel of sheet iron 

 or other metal, through the centre of which passes a spindle a c, having 

 a collar at a, upon which the float is screwed down by a nut outside. 

 At the upper end e is fixed a cap of brass with a joint ground steam- 

 tight to the bottom of the whistle y"; dcd is a stay Uirough which 

 the spindle a c passes, having sufficient clearance in the hole at c. 

 This stay may be either double, as shown, or single. At i is a cotter 

 which prevents the spindle dropping farther than the distance from 

 the bottom of the cotter to the stay at c; gh is the surface of the 

 water. 



When the steam is down, the cotter in the spindle rests upon the 

 stay, through which the spindle passes leaving the passage at e open. 

 As soon as the steam rises, the vessel iakb hlls with steam and rises 

 to the position shown in the sketch. When the water falls the float 

 also falls, leaving the passage to the whistle open, and is stopped in 

 its descent, as above described, by the cotter 6 resting on the stay. 

 There are holes at the sides of the cup e as well as a passage through 

 the top to prevent the lodgment of dirt, &c. 



The advantage which I think this apparatus possesses above any I 

 have yet seen, is the absence of any working joints, there being only 



" .Some qualities w ill stand the fire remarkably w ell.— Ed. 



two points of contact required, at e and c, and those leaving clearance. 

 The whistle will also act as a vacuum valve when the steam goes 

 down; for it is evident that when the steam is below the pressure of 

 the atmosphere, it will be condensed in the float vessel, which will 

 consequently fall by its own gravity. 



I am, Sir, 



Your's obediently. 

 Liverpool, May 15. G. J. Horner. 



KORTH OF ENGLAND RAILWAY CHAIR. 



^~e.>j:..- .., '^^ 



A, section from 1 to 2. — B. plan of chair. — C, section from 5 to 6. — D. 

 ditto, locking cheek in its place. — E, ditto, rail. — F, ditto, from 3 to 4.— G 

 and H, side and end of locking cheek. — K, malleable iron key or wedge. — L. 

 stone blocks, or wood sleepers. 



Sir — I beg to hand you a sketch of a joint chair with some expla- 

 nation, &c., and a section of the rail used on the Great North of 

 England Railway, which are at your service. The chair is considered 

 to be well adapted to the rail, and simple in its principle. The middle 

 chair, as well as the cheek chairs, are on the same construction, but 

 vary in the weight : 



Joint chair 40 iti. 



Middle do 41 



Cheek do 30 



Rail per yard lineal 60 



The railway has now been opened since the beginning of last April, 

 and keeps in a good working condition, there are very few slips or 

 subsidence in any of the embankments or cuttings. From the easy 

 gradients, solidity of execution, and other favourable features con- 

 nected with the Great North of England Railway, it readily may be 

 inferred that the line will be worked at less cost than any other line 

 of the same extent. 



I am. Sir, 



Your obedient servant, 

 York, May 12. M. Q. 



GREEWVICU RAILWAY. 



List of tenders of the third contract for mdeniug the railway between 

 the London terminus and the Croydon Junction, delivered iu on the ?7th 

 April last. 



Mr. Jackson fll.GOS 



Messrs. Ward 11,892 



Mr. GrimsdeU 11,947 



Messrs. Grissell and Peto 12.275 



Mr. Bennett 12,350 



Messrs. Baker 12,380 



Messrs. Little 12,100 



Messrs. Lee 13,333 



Mr. Mundy 13,528 



Messrs. Piper 13,050 



