GEOLOGICAL SURVEY OF OHIO. 13: 
and hence industries have been established at sites which are now known 
to be unfavorable, and where the local supplies must be rejected and 
others transported at a great permanent disadvantage if the output reaches. 
a grade where its use is safe and proper. Also chemists whose train- 
ing has been so directed as to give them facility in the class of problems 
here met are exceedingly scarce, and thus many plants have gotten 
into the way of running along with only the baldest daily essentials from 
the laboratory instead of asking and receiving from the chemist that 
class of information and advice which would enable them to rapidly 
conquer the obstacles and smooth away the difficulties which every new 
cement industry must inevitably face. Also, managers and directors of 
cement industries, not being able to obtain in any place a succinct state- 
ment of what has been done in this field of research, have sometimes 
adopted mistaken and dangerous policies as to their product, because the- 
defects arising are mostly slow to develop and obscure, and have thus 
placed upon the market thousands of barrels of poor material whose use 
tends to discredit cements as a class, and prevent the superlative useful- 
ness of good cements from being earlier and more fully recognized. 
It has been my intent and desire in authorizing and supervising the 
preparation of a bulletin on this subject to place within the reach of every 
intelligent person who desires it a statement of what materials are needed 
to make good cements, of what mechanical treatment is necessary, and 
what effects will result from deviations from the prescribed quality of 
materials or treatment. It is not possible to convey these ideas without: 
constant use of chemical nomenclature and chemical conceptions. | 
Mr. Bleininger’s work is contained in this volume, as Bulletin No. 3. 
It may be that the book will be a disappointment on this account to. 
some persons who are interested in the industry, but who have not the: 
training to readily grasp chemical conceptions. It has been written under 
the belief that the cement industry is really a branch of chemical engin- 
eering and that no one devoid of chemical and engineering training can 
be safely placed in control or high in the councils of this industry. To 
cement chemists, and managers of plants, the work will doubtless be 
readily accessible and it is hoped that the practical conclusions reached in 
all parts of the book will be available to all interested persons, whether 
the reasoning and investigations by which the conclusions are reached 
are equally clear or not. | 
I wish to record at this place my high appreciation of the work which 
Mr. Bleininger has put upon-this volume. Hus search of the literature 
has been as thorough as his opportunities have afforded; his own lab- 
oratory researches have been most painstaking and laborious, and as a 
rule have been done by his own hands, in the intervals of his daily busy 
routine. His acquaintance with the various plants of the country is by no 
means confined to Ohio, as he covered the country in the course of. his. 
