CHAPTER XXVII.

WATER FOR LOCOMOTIVE BOILERS 359

How Water gets mixed with Lime.--Expense entailed by using Bad Water.--Efforts of Master Mechanics to secure Good Water.--Loss of Faith in Purifying Methods.-- Scale-making Agencies.--To Ascertain the Quality of Water.--Appliances needed in Testing Water.--Preparing for the Experiments.--Lime held in Solution by Free Carbonic Acid.--Test for Lime Salts.--Test for Sulphate of Lime.--Test for Carbonate of Magnesia.--Test for Salts of Iron.--Test for Chlorine.--Learning the Manipulation of Tests.--Making Qualitative Tests.--The Soap-test for Hardness.--Modification of the Clark Soap-test.--Applying the Soap-test.--Difficulties of purifying Water for Locomotives.--Mud.--Carbonate of Lime.