45, COENH1LL, E.G., AND 122, BEGENT STREET, W., LONDON. 189 



TO USE THE SALINOMETER. 



5 1 9 Fill the Assay Jar from the Boiler, suspend the Thermometer in the side 

 partition of it, and immerse the Ball in the water ; then at whatever division on the 

 stem it rests level with the snrface, will be the degrees of saline matter contained 

 in the water at the temperature of 200 ; but if the heat of the water varies below 

 that degree, the following scale of temperature will be the blowing-off point : 



TEMPERATUKE. 200 -^1 



180 |f } at surface for Blowing-ofC point. 

 160 sf I 



Under the circumstances at which fresh water boils at 212, sea water boils 

 at 213'2. The boiling temperature is raised by the chemical solution of any 

 substance in the water, increasing with amount of matter dissolved. For this 

 reason, marine engineers use a Thermometer to determine the amount of salts held 

 in solution by the water in the boilers of sea- going steamers. Common sea water 

 contains about -| s of its volume of salt and other earthy matters. As evaporation 

 proceeds, the solution becomes proportionally stronger, and more heat is required 

 to produce steam. The following table by Messrs. Main and Brown shows the 

 relation between the boiling point under the mean pressure of the atmosphere, or 

 30 inches of mercury, and the proportion of matter dissolved in the water. 



When the salts in solution amount to || the water is saturated. It has also 

 been ascertained that, when a solution of -\ is attained, incrustation of the sub- 

 stances commences on the boiler. Hence it is a rule with engineers to expel some of 

 tlie saturated water, when the thermometer indicates a temperature of 216 F, and 

 replace it with fresh water, in order to prevent incrustation and injury to the boiler. 



520 The Boiling point of Saturated Solution of Salt varies from 218 degrees to 

 226 Fahr. 



Proportion of Salt in 400 parts of water . . Boiling point 212 



-53 213-2 



214-4 

 215-5 



3V 

 * 



216-6 

 217-9 

 219-0 

 220-2 

 221-4 

 222-5 



223-7 

 224-9 



if . . 226-0 



For further information on this subject, see Temperature Thermometer in 

 conjunction with pressure gauges, page 151. 



521 Salinometer, or Salt Water Guage, (How's Patent), constructed of strong Gun 



Metal and Brass, for attaching to the Boilers of Marine Steam Ships, to 

 ascertain at any moment the specific gravity of the water contained in the 

 Boiler. Complete, with Metal Salinometer, Thermometer, and Lamp ; best 

 finished Gun Metal Tap Unions and Yalves. 880 



522 Salinometer, Saunders 880 



523 Ditto, Gambles . .880 



