Prof. Campbell's Invention Saves Cement Men Money

PROF. CAMPBELL'S INVENTION SAVES CEMENT MEN MONEY

By the invention of Professor Edward D. Campbell, Michigan's renowned instructor who lost his eyesight in the cause of science, a great amount of money will be saved annually in the cement industries of the country. It has been determined by him that it makes a difference at what degree the marl is melted in order to preserve its stability and hardness, and the fact that he has determined upon a method of finding out what temperature is necessary for the best results in cement softening makes it possible to put in practice what has hitherto only been theory. The machinery which is made to accomplish these results consists of a cement mill which was made here in the University about two years ago, a gasoline blow flame and a galvanometer. In this is tested the marl that is sent here from all of the central states and so perfect is the apparatus that the temperature at which it ought to be melted to make the best cement can be registered to fractions of a degree. In the hollow Iron cylinder into which one wire of platinum and one of an alloy of rhodium and platinum extend, is placed the marl and the cylinder revolves for several days while making a test. The electric current from the wires passes to a galvanometer, which registers so finely that the fractions can be read with the aide of a microscope. So great is the heat used in the experiments and so well regulated in the apparatus that heat can be used up to the melting point of the wires. It is said that the heat sometimes reaches 3,200 degrees.

The importance of the results obtained in this wise can hardly be overestimated by cement men of the country, and it would be hard to estimate the amount of money the invention will save in a few years.