174 



NEGBETTI AND ZAMBRA, HOLBOEN VIADUCT, E.G., 



FIG. 414. FIG. 415. 



STEAM PRESSURE GAUGES. 



FIG. 414*. 



409 The almost daily occurrence of frightful accidents from the explosion of 

 steam boilers calls for the utmost vigilance and care from owners and employers of 

 steam power. One of the most important precautions is that of having accurate and 

 reliable gauges. Too much stress cannot be laid upon this point, for if, from motives 

 of false economy, cheap and carelessly made gauges are used, their indications can 

 never be depended upon, and their use may lead to fatal and costly results. It has fre- 

 quently come under the notice of Messrs. Negretti and Zambra that Steam Gauges 

 have been supplied or repaired by persons without the slightest knowledge of their 

 construction, or having any means of proving or testing ; consequently they have 

 been found fearfully in error, and worse than useless because unsafe. 



410 Steam Gauges, Mercurial, from 10 to 140 Ibs., with union joint at 



either side of the frame, in polished Mahogany frame . . .2 



411 Ditto, ditto, Brass ditto 3 



412 Thermometric Pressure Gauge, for showing the pressure of Steam 



by taking its temperature (fig. 372), Iron mountings . . .1 



413 Ditto ditto, Brass mountings (figs. 362 and 367) 2 



414 Ditto ditto, ditto with Bent tubes, as figs. 409 and 409*, 



screw flanges and stuffing boxes, &c., for high pressures from 330 



415 Angle Thermometers, for Yacuum Sugar Pans, Brass Mounted 



(fig. 415) 1 16 



416 Thermometric Pressure Gauges with Temperature and Pressure 



Scales made of any length to order or drawings, with either English 

 or French divisions. 



10 

 10 



