Go this Summer Colorado Santa Fe Ask Passenger Department, Railway Exchange, Chicago booklet. Very low excursion This edition (copyright May, 1906) now being delivered us by the printers, consists of four volumes bound in 4 red morocco, treating on all topics of interest and value to the machinist, tool maker, blacksmith, foundryman, patternmaker, sheet metal worker, draftsman, steam and gas engine engineers, electricians, etc. A COMPLETE SET FREE FOR INSPECTION The set handles each subject in a thorough, practical manner, free from difficult mathematics. It is edited and compiled with the view of assisting the quick understanding of the reader, each volume containing a complete set of test questions, enabling the reader to refresh his mind on the several topics. Each volume contains a number of formulas and tables of great working value. The work is profusely illustrated, printed on good paper, standard size type. With the first installment of books now being delivered us, we propose to introduce the complete work at a price regardless of its real worth. The Regular Price of These Four Volumes is $24.00 Per Set This valuable work is made up from the representative instruction papers issued by the We will send you the complete set of books, express paid, subject to five days' examination and approval, FREE. Send us $1.00 down and $1.00 for eleven months thereafter. If you wish to pay cash, then remit $10.80, allowing yourself a cash discount of $1.20. If the books are not satisfactory, notify us and we will send for them. PARTIAL TABLE OF CONTENTS CUT OUT AND MAIL TO-DAY American School of Correspondence Chicago, Ill. prepaid) one "Cyclopedia of Modern Shop Practice," Please send me FREE on five days' approval (express pay $1.00 and $1.00 per month for eleven for the books. Cash with order $10.80. Money refunded if not satisfactory. months; otherwise I will notify you to send (regular price $24.00). If satisfactory, I agree to Name .................... Address.. Vol. I. Machine Shop Work, Lathe. Planer, Shaper, Milling Machine, Grinding Machine; Tool Making, Hardening, Thread Cutting Dies, Drill Jigs, Motor Driven Shops. Vol. II. Pattern Making; Machine Design; Metallurgy: Foundry Work, Steel Castings; Brass Work; Shop Management. Vol. III. Gas and Oil Engines: Producer Plants; Care and Management of Gas Engine; Automobiles; Elevators; Construction of Boilers; Steam Engine; Steam Turbine; Management of Dynamos and Motors; Electric Wiring. Vol. IV. Forging, Welding. Tool Forging and Tempering, Electric Welding; Sheet Metal Work: Tinsmithing; Mechanical Drawing, Working Drawings, Shop Drawings; Mechanism. ...... T.W. 8-06 PROF. J. J. THOMSON, OF CAMBRIDGE UNIVERSITY. Born in Manchester, Eng., in 1856. Cavendish Professor of Experimental Physics in Cambridge University since 1884. Most conspicuous figure in the development of the physics of the "electron" and in investigations upon the connection between electricity and matter. THE TECHNICAL WORLD MAGAZINE Volume V AUGUST, 1906 No. 6 Are the Elements Transmutable? By Robert A. Millikan, Ph. D. Assistant Professor of Physics in The University of Chicago O one can observe and reflect upon even the simplest facts of nature, without soon coming to the conclusion that the thousands of different types of matter which we find about us in this world are not all independent and distinct substances; for at every turn we see one form of matter being transformed into another, or two or three forms coming together and giving rise to a third. Thus, we heat water, and it changes into steam; we touch a match to gunpowder, and it is gone; but the smoke and odors in the air quickly inform us that some new substances have been produced. How many ultimate forms of matter are there then? And how many of the manifold substances in the world are only compounds of these elementary substances? This question was first propounded thousands of years ago, and an absolutely certain answer has not yet been found. This does not mean, however, that no progress has been made toward its solution. My purpose in the present article is to give a brief record of the attempts of man to unlock this most profound of nature's secrets, and to show to what extent he has thus far succeeded, and what remains still unknown. Greek Speculations The earliest Greek philosopher, Thales, about 600 B. C., taught that water is the fundamental principle of all things. Xenophanes, who came a hundred years later, held that there were two fundamental principles-air and water; while Hippocrates (460 to 377 B. C.), the "Father of Medicine," first launched the doctrine that there were four elementary substances-earth, air, fire, and water. His argument for a number of elements instead of one, is rather naive. It was something like this:-If man were composed of a single element, he could never be ill, but since he is at times ill, and requires complex remedies to keep him. well, he must himself be complex. Aristotle (380 to 322 B. C.) added to the four elements of Hippocrates a fifththe ether, eternal and unchangeable, the ultimate substance of which the four elements are formed. And this Aristotelian philosophy of matter held sway Copyright, 1906, by The Technical World Company (591) |