Apeil 30, 1909] 



SCIENCE 



691 



after he had come to fulness of years without 

 any break in his intellectual vigor. 



He was born at Tribes Hill, N. T., on 

 October 24, 1836. His ancestors on both sides 

 were German, and old settlers in the Mohawk 

 Valley, the first Hough having come to this 

 country in 1730 from Wiirtemburg. 



Professor Hough was a born astronomer, 

 and grew up filled with the idea of following 

 that profession; it is said that at nine years 

 of age he constructed a contrivance from fish- 

 poles for measuring the right ascension of a 

 star. His mechanical genius, which he in- 

 herited from his father, also became manifest 

 about this time, and he harnessed up a small 

 brook to do his mother's churning. 



After completing the course in the graded 

 schools and! the Seneca Falls Academy, he 

 entered Union College at Schenectady, N. Y., 

 where he graduated in 1856 with high honors. 



After graduation he became principal of the 

 first ward school in Dubuque, Iowa, where 

 he remained until 1858, when he entered Har- 

 vard University for post-graduate work, taking 

 the degree of A.M. in 1859. The same year 

 he became assistant astronomer at the Cin- 

 cinnati Observatory. 



In 1860 he went to the Dudley Observatory 

 at Albany, N. T., as assistant astronomer, and 

 two years later was appointed director, which 

 position he held until 18Y4. It was at the 

 Dudley Observatory that a large amount of his 

 valuable work was done. 



His astronomical work consisted largely in 

 the observations of the declination of stars 

 compared with Mars, observations of the 

 planet Neptune, and of asteroids, and observa- 

 tion of Nautical Almanac stars, standard 

 zone stars and small planets. 



He invented at this time a machine for 

 cataloguing and charting stars, the principle 

 of which depends on the magnifying by me- 

 chanical means the angular motion of the 

 telescope. 



In 1867 he began work on the measurement 

 of Struve's list of close double stars, and dur- 

 ing the same year made a long series of in- 

 vestigations to determine the amount of the 

 personal equation in transit observations. He 

 made, besides, valuable observations on the 



rate of the sidereal clock, and the compensa- 

 tion of the pendulum. 



A large part of his time and attention at 

 the Dudley Observatory was given to meteor- 

 ological work, and in 1865 he invented his 

 recording and printing barometer. The prin- 

 ciple of this instrument consists in the trans- 

 mission of changes in the level of the mercury, 

 by a float resting on the surface of the mer- 

 cury in the short arm of a syphon barometer. 

 The movements of the float are transmitted by 

 electricity to the moving parts of the mechan- 

 ism, which repeat this motion and record it. 

 His reports show that more than 50,000 barom- 

 eter observations were made with this machine 

 in five years. He was awarded a gold medal 

 for this instrument at the Centennial Exhibi- 

 tion in Philadelphia in 1876, and many years 

 later he received a medal for the same instru- 

 ment at the World's Fair in Chicago in 1893. 



Another machine invented at this time was 

 the meteorograph, a machine of simpler con- 

 struction, which registered hourly the barom- 

 eter and wet-and-dry-bulb thermometers. Sev- 

 eral of the two machines mentioned above 

 were constructed for the United States gov- 

 ernment. 



He also invented an automatic anemometer, 

 which records the velocity of the wind in the 

 form of a curve, prints the results hourly in 

 miles, and also gives the direction, electricity 

 being used as the active agent. He published 

 a long series of observations made with this 

 machine, and was one of the first to point out 

 the intimate connection between atmospheric 

 pressure and the direction of the wind. 



Besides these instruments, he invented the 

 first horizontally-driven machine-saw, and also 

 began work on his printing chronograph. He 

 was an expert mechanic, and did all the work 

 on his machines with his own hands. 



In 1868 he made a long series of investiga- 

 tions on the Daniel or gravity battery, and 

 was the first to show that lead may be advan- 

 tageously substituted for copper as the nega- 

 tive plate. He also showed that the substi- 

 tution of a cell of leather 0.06 inch thick in 

 place of the porous clay cell in the battery 

 produced double the amount of current. 

 Moreover, that the quantity of electricity 



