Besides this, I could not hold myself entirely aloof from public affairs, and was three times sent by the Government of the United States to do public duty abroad: first as a commissioner to Santo Domingo, in 1870; afterward as minister to Germany, in 1879; finally, as minister to Russia, in 1892; and was also called upon by the State of New York to do considerable labor in connection with international exhibitions at Philadelphia and at Paris.
I was also obliged from time to time to throw off by travel the effects of overwork.
The variety of residence and occupation arising from these causes may perhaps explain some peculiarities in this book which might otherwise puzzle my reader.
While these journeyings have enabled me to collect materials over a very wide range--in the New World, from Quebec to Santo Domingo and from Boston to Mexico, San Francisco, and Seattle, and in the Old World from Trondhjem to Cairo and from St.Petersburg to Palermo--they have often obliged me to write under circumstances not very favorable: sometimes on an Atlantic steamer, sometimes on a Nile boat, and not only in my own library at Cornell, but in those of Berlin, Helsingfors, Munich, Florence, and the British Museum.

This fact will explain to the benevolent reader not only the citation of different editions of the same authority in different chapters, but some iterations which in the steady quiet of my own library would not have been made.
It has been my constant endeavour to write for the general reader, avoiding scholastic and technical terms as much as possible and stating the truth simply as it presents itself to me.
That errors of omission and commission will be found here and there is probable--nay, certain; but the substance of the book will, I believe, be found fully true.

I am encouraged in this belief by the fact that, of the three bitter attacks which this work in its earlier form has already encountered, one was purely declamatory, objurgatory, and hortatory, and the others based upon ignorance of facts easily pointed out.
And here I must express my thanks to those who have aided me.

First and above all to my former student and dear friend, Prof.George Lincoln Burr, of Cornell University, to whose contributions, suggestions, criticisms, and cautions I am most deeply indebted; also to my friends U.G.Weatherly, formerly Travelling Fellow of Cornell, and now Assistant Professor in the University of Indiana,--Prof.and Mrs.Earl Barnes and Prof.William H.Hudson, of Stanford University,--and Prof.
E.P Evans, formerly of the University of Michigan, but now of Munich, for extensive aid in researches upon the lines I have indicated to them, but which I could never have prosecuted without their co-operation.
In libraries at home and abroad they have all worked for me most effectively, and I am deeply grateful to them.
This book is presented as a sort of Festschrift--a tribute to Cornell University as it enters the second quarter-century of its existence, and probably my last tribute.
The ideas for which so bitter a struggle was made at its foundation have triumphed.

Its faculty, numbering over one hundred and, fifty; its students, numbering but little short of two thousand; its noble buildings and equipment; the munificent gifts, now amounting to millions of dollars, which it has received from public-spirited men and women; the evidences of public confidence on all sides; and, above all, the adoption of its cardinal principles and main features by various institutions of learning in other States, show this abundantly.