Thirty-fourth Annual Meeting 317 
developed there threatened to make agreement upon definitions of the 
principal electrical units impossible. The Franklin Institute now 
exhibits a sheet of paper on which Dr. Mendenhall one evening wrote 
down definitions of the ampere, the volt and the ohm. These he pre- 
sented next morning to the Chamber of delegates; and the definitions 
finally adopted are practically identical with his penciled memorandum. 
In 1894 he began a seven year service as president of the Worcester 
Polytechnic Institute. 
His work as an investigator and as an organizer of research was 
indeed notable, but he also had a most unusual gift for making the 
results of scientific work intelligible and interesting to popular audi- 
ences. As a consequence he has been for many years repeatedly called 
upon for memorial and dedicatory addresses. In 1892 he gave a Convo- 
cation Address at Johns Hopkins on ‘‘ Measurements of Precision, con- 
sidered in Their Relation to the Condition of Man,” and the same year 
prepared the principal address for the dedication of the new Ryerson 
Laboratory of the University of Chicago. He gave two series of lectures 
at the famous Lowell Institute in Boston, one in 1882 and one in 1892. 
Also lectures at Cooper Union, New York and in Philadelphia, Balti- 
more and Washington. In 1887 he was made a member of the National 
Academy of Sciences. In 1888 he was president of the American Asso- 
ciation for the Advancement of Science and won golden opinions as 
presiding officer of the Toronto Meeting. The next year he gave the 
retiring presidential address at Indianapolis. In 1894 he gave an address 
as retiring president of the Philosophical Society of Washington. Many 
of us here remember the delightful address he gave a few years ago as 
president of our own Ohio Academy of Science and his address on 
“Some Metrological Memories”’ before the Franklin Institute in 1918. 
His work has been recognized by the award of numerous decorations 
and medals. From the Paris Exposition in 1900 he received a medal for 
a monograph entitled ‘‘Scientific, Technical and Engineering Education 
in the United States,” from the Imperial Education Society of Japan 
in 1911 a gold medal. The same year he was decorated with the Order of 
Sacred Treasures, Japan. The receipt of the gold medal of the Franklin 
Institute has already been mentioned. 
These are but a few of the high points of achievement in a notable 
career in physical science. 
Mention has already been made of his pioneer work in equipping and 
developing the physical laboratory of the Ohio State University and - 
this is but a small part of his service to that institution. His wise selec- 
tion of equipment is shown in the fact that many of his early purchases 
are still giving good service on lecture table and in laboratory. His 
inspiring leadership of many of the early graduates, such as C. F. 
Marvin, W. C. Sabine; C. F. Scott, gave them a real start in their 
notable scientific careers. 
Professor Derby, one of his confreres on the faculty in the 80's, has 
written concerning his important part in determining the educational 
policy of the institution as follows: ‘In every faculty certain members 
are conceded leadership. It soon became plain to me that in questions of 
