th of the duke Gauss continued in
Braunschweig, but his small allowance, and the absence of scientific
company made a change desirable. Through Olbers and Heeren he received
a call to the directorate of Gottingen University in 1807, and at once
accepted it. He took a house near the chemical laboratory, to which he
brought his wife and family. The building of the observatory, delayed
for want of funds, was finished in 1816, and a year or two later it was
fully equipped with instruments.

In 1819, Gauss measured a degree of latitude between Gottingen and
Altona. In geodesy he invented the heliotrope, by which the sunlight
reflected from a mirror is used as a "sight" for the theodolite at a
great distance. Through Professor William Weber he was introduced to
the science of electro-magnetism, and they devised an experimental
telegraph, chiefly for sending time signals, between the Observatory and
the Physical Cabinet of the University. The mirror receiving instrument
employed was the heavy prototype of the delicate reflecting galvanometer
of Sir William Thomson. In 1834 messages were transmitted through the
line in presence of H.R.H. the Duke of Cambridge; but it was hardly
fitted for general use. In 1883 (?) he published an absolute system of
magnetic measurements.

On July 16, 1849, the jubilee of Gauss was celebrated at the University;
the famous Jacobi, Miller of Cambridge, and others, taking part in it.
After this he completed several works already begun, read a great deal
of German and foreign literature, and visited the Museum daily between
eleven and one o'clock.

In the winters of 1854-5 Gauss complained of his declining health,
and on the morning of February 23, 1855, about five minutes past one
o'clock, he breathed his last. He was laid on a bed of laurels, and
buried by his friends. A granite pillar marks his resting-place at
Gottingen.

II. WILLIAM EDWARD WEBER.

WILLIAM EDWARD WEBER was born on October 24, 1804, at Wittenberg, where
his father, Michael Weber, was professor of theology. William was the
second of three brothers, all of whom were distinguished by an aptitude
for the study of science. After the dissolution of the University of
Wittenberg his father was transferred to Halle in 1815. William had
received his first lessons from his father, but was now sent to the
Orphan Asylum and Grammar School at Halle. After that he entered the
University, and devoted himself to natural philosophy. He