The exhaustion within a comparatively short time of the first edition of " A Practical Treatise on Friction, Lubrication, Fats and Oils" and the constant demand for it, are the best evidence that it has given satisfaction, and no apology is therefore necessary for presenting the second edition.

While but few alterations have been made in the text of the book and no essential portions have been omitted, it has been thoroughly re-revised and considerable new matter, particularly a number of useful formulas for lubricants from abroad, has been introduced, as well as a review of the efforts and progress made during the last decade in the petroleum industry.

I wish to state that I cordially agree with the timely criticism the editor of "The Petroleum News", published in Cleveland, Ohio, has made about the lamentable lack of proper facilities in the laboratories of colleges and schools of science for more practical instruction for young students of chemistry to make researches on a scientific basis of the petroleum industry so valuable to the prosperity of the country. Congressional action is too slow and too indifferent, but moneyed philanthropists could ingratiate and distinguish themselves by the foundation and endowment of a practical laboratory conducted by able chemists in conjunction with intelligent practical oil men, where investigations of progressive conceptions could be tested and developed on a practical scale. Many rich men have obtained their wealth not by improvements conceived by them, but by speculations on the commercial value of the petroleum industry.

E. F. Dieterichs. Cleveland, Ohio. December, 1915.