256 



The Country Gentleman'' s Magazine 



from its name it ouglit to be tlie safest place. 

 Very much in name only, do we fear, that 

 many of our safety-valves are " safety." In 

 the reports of the Manchester Steam-Boiler 

 Association there is scarcely more frequent 

 reference made to any point than to the 

 dangers arising from non-attention to the 

 safety-valves of boilers so as to ensure their 

 being in working order. They are found 



\ h I 



-J-^ 



Fig. II. 



overweighted, tied down to prevent their rising, 

 and left for long in such a neglected condi- 

 tion that they stick in their seats, or the lever 

 is found to stick in the joints. The last is a 

 very common occurrence, and the most 

 practical remedy we know of is to have brass 

 washers {a a, fig. n) inserted between the 

 sides of the lever b and the standard cc; 

 while a brass pin {d d) should be passed 



d:w'-^f--^ 



m 



through all in place of a steel or iron one. 

 The brass being free from corrosion, the lever 

 will not stick in the joints from rust ; but the 

 attendant should nevertheless be most care- 

 ful in seeing that the safety-valve does work. 

 In Nasrayth's safety-valve (see fig. 12) there is 

 little danger of the valve c sticking in its seat, 

 as it is spherical, and rests upon a conical 

 seat, so that the contact is reduced to a mini- 



mum ; and by the further addition of a sheet- 

 iron flap {b), which is being continually acted 

 upon by the surging boiling water and steam, 

 the valve is kept in a continual state of motion 

 in its seat. No overweighing of the valve is 

 possible,- as the valve is weighted inside the 

 boiler, and externally it is surrounded by an 



3E 



■Lq 



Fig. 13. 



iron cap, as in the engraving, pierced with 

 holes through which the steam escapes. A 

 valuable feature of this valve is the direct 

 action of the weight upon it, without the in- 

 tervention of any jointed levers, which,, as 

 already pointed out, are so apt to get out of 

 order. In fig. 13 we give a drawing of the 

 arrangement of Mr Fairbairn, the eminent 

 engineer, by which all tampering with the 

 weight of the valve is prevented, and by 

 which the valve can be lifted now and then 

 out of its seat to prevent sinking. This 

 good in many respects is so far defective, as 

 it depends upon the care of the attendant. 



The careful attention of the stocker or tenter 

 to the supply of 7uater to the boiler is abso- 

 lutely demanded if safety is required. The 

 appliances to guide him in his judgment in this 

 important department of boiler management 

 are numerous — in many cases too numerous. 

 They may be reduced to three — first, the 

 " float or water-feed apparatus and indicator;" 

 second, the " water and steam-cocks or 

 gauges ;" and third, the " water-glass gauge." 

 There is a by no means uncommon notion 

 afloat that if any one of these appliances is 

 alone used, that that is sufficient. Now, let 

 the reader take it for granted that all three 

 are needed in a good boiler designed to be 

 worked safely. The " feed apparatus" of 

 boilers vary much in arrangement ; indeed, 

 the name is legion, so many inventors having 

 brought out this and that form. Appliances 



