The author in planning the outlines of this work has aimed to keep close to real things belonging to the practical side of hydraulics, pumps, pumping-engines, and to the simple explanation of the Natural Laws pertaining to their industrial application. A knowledge of the real things in the objective world about us and the laws that govern them in their inter-relations is of practical value to every man; all branches of science are simply branches of one great science and all phases of human activity are touched by it; man is so constituted that he must have something to be interested in, and if he has no resources within himself he looks elsewhere, and often to his own disadvantage. And so, the author has aimed to make the subjects of this book interesting as well as useful; 1, by their self-help arrangement; 2, by the illustrations, and 3, by leaving very much to the further research and investigation of the reader, as, in a well-told story, many things are left to the imagination of the listeners. It should be borne in mind by the reader, that the work is designed to be seriously Educational in its plan and scope, and Progressive in the presentation of its subject-matter; nothing has been withheld that might add to its lasting value. This is said in the way of an introduction to the _Table of Contents_ to which the student is referred as showing the method of treatment, in the wide range of the theory and practice, of this important branch of Industrial Science. In the back of the volume may be found a _Ready Reference Index_ which by its admirable method of arrangement affords a speedy key to the contents of the book when occasion requires. WHAT A STEAM PUMP WOULD SAY IF IT COULD TALK. _The well-known pump expert, Mr. F. Meriam Wheeler_, writes us saying that if the manufacturers of steam pumps would send out with their pumps a card reading something like the following, it would probably impress the men who run the pumps more forcibly than anything that could be said or written in the ordinary way of giving instructions: “_Please do not gorge me with oil, as it will give my steam chest indigestion. What I like is a steady diet and thus enable my valves to work smoothly and with durability. A very small amount of oil fed to me steadily is the thing—it saves oil and repair bills._ “_Two or three times a year give me a good dose of kerosene, to clean out any obstructions that may have accumulated in the passageways of my steam chest, or on the face or working parts of the valve and valve-seat, or on the chest piston._ “_Do all you can to help me make a full length of stroke, as it means that I will use less steam and do better work. The adjustable collars on the valve rod will allow you to regulate the length of my stroke to a nicety._