The record of a half century devoted to scientific work

Professor Charles R. Cross, who will be accorded a well merited period of rest after forty-six years of the greatest devotion to the Institute, was born in Troy and for many years past has been a resident of Brookline. He is an alumnus of M. I. T., receiving his degree in 1870 with the third class to graduate, and since that time has been a member of the Institute teaching staff. He returned to Tech the fall following Commencement as an instructor and from 1871 till 1874 was assistant professor in physics. The next year his official title included astronomy and from 1875 till 1878 it was descriptive astronomy that he taught in addition to physics. Since 1878 he has been Thayer professor of physics and since 1886 also director of the Rogers Laboratory of Physics.

Professor Cross has been a foremost figure not only in the Institute but in the scientific world; not only in the development of technical education but in work of investigation in various specialties. As a consulting physicist his opinions in the matter of the telephone are historic and in another division of his specialty, that of acoustics, he stands at the head of investigators who have given attention to its musical aspects. Within the Institute he has rendered enduring service by his long continued devotion and enthusiasm. By the establishment of courses in electrical engineering he earned the gratitude of the whole educational world. Recognizing the need of such study in which he was indeed the pioneer, he began in the early eighties the instruction of this specialty as a part of the department of physics. He instituted the courses, developed them and bore the brunt of the introduction of a new line of special education to the world. In the late nineties electrical engineering became a separate department at Tech, one

of the exceedingly important ones in touch with the needs of modern industries. Education owes a great debt to Professor Cross for his foresightedness, the courage of his own convictions and the will power and industry necessary to carry them out.

Within the domain of physics in its more restricted sense, Professor Cross developed the work of experimental lecturing, with great inventive power and discernment and incredible labor in evolving the technique. The line of experimentation in his courses is exceedingly elaborate, and the wealth of material and the methods of handling assembled and developed under his care place Technology at the head of all institutions in this fascinating work.

Outside the Institute Professor Cross has the highest reputation for the quality of his attainments. He is a member of many scientific associations here and abroad and, in the larger world, a foundation member and past president of the Appalachian Mountain Club. In the American Academy of Arts and Sciences he has been for a long time chairman of the Rumford Fund Committee, a most important function devoted to the forwarding of scientific research, and in the great American Association for the Advancement of Science, he is chairman of the Research Committee of the Committee of One Hundred. In the professional world he has been often employed in consultation in most important interests.

THE WORK OF PROFESSOR CROSS AT THE

INSTITUTE

BY A COLLEAGUE

Professor Cross has occupied a unique position in the Institute of Technology. In his own person he embodies almost its whole existence more than fifty years. He entered as a second-year student in 1867, when the Institute had but recently left its first cramped quarters on Summer street for the daring magnificence of the Rogers Building, he retires after a year in a vast edifice beside which old Rogers seems modest enough. In the meantime he has, during thirty-three years, occupied quarters of his own planning in the Walker Building. He was student-assistant in German in his fourth year, instructor in physics for a year, then, at a tender academic age, assistant professor. He has thus been a colleague of every member the Faculty has ever had, save only eight—most of them his teachers who had retired before his appointment. Of the present Faculty a very large proportion have been his students before becoming his colleagues.

In another notable respect Professor Cross's status is unique. The Institute curricula have always been founded on mathematics, chemistry and physics; they have always included English, history and modern languages as common elements. In most of these subjects, however, classes have been subdivided among several teachers, and in all of them, professors have come and gone after longer or shorter terms. In physics, alone, one man has lectured year in and year out to all second-year students for nearly thirty years, only since 1903 relinquishing half the class to an associate. Thus Professor Cross has taught an incomparably larger proportion of all Tech men than any other member of its Faculty. To thousands of them "Charlie Cross's" lectures in second-year physics are still-however much or little enjoyed at the time-models of clear and elegant scientific exposition. Living in a period of marvellous scientific inventions, with not a few of which his own professional contact has been intimate and important, he has brought to his lectures a continual wealth of fresh experimental illustrations.

The vitality of the course in physics during all these years has been conspicuously shown both by the scientific distinction of the