KEOKUK 



3232 



KEPLER 



& Quincy, the Chicago, Rock Island & Pacific, 

 the Toledo, Peoria & Western and the Wabash 

 railroads, and by river steamboat lines. The 

 Keokuk and Hamilton (111.) bridge, first built 

 in 1873, was reconstructed in 1915 into a 

 double-deck bridge; the lower level is used by 

 railroad and the interurban lines, the upper 

 level for highway traffic. The area of the city 

 exceeds four square miles. In 1910 the popu- 

 lation was 14,008; as reported by the state 

 census of 1915 it was 15,239. 



Across the Mississippi at this point, and be- 

 low the Des Moines rapids, is a $27,000,000 

 power dam (see below). Keokuk contains 

 Rand, Bluff and Kelbourne parks, a $100,000 

 Federal building, Y. M. C. A. building, Ma- 

 sonic Temple, public library, Saint Joseph and 

 Graham hospitals and a Home for the Friend- 

 less. Here also are located the Keokuk Medi- 

 cal College, a dental school, a school of phar- 

 macy and Saint Vincent's Academy. Near the 

 city is a national cemetery. 



Settlement at this place began about 1820, 

 but progressed slowly until 1836. The town 

 was laid out in 1837 and named in honor of 

 Keokuk, an Indian chief. His grave and a 

 monument to his memory are in Rand Park. 

 The town received a city charter in 1848. The 

 commission form of government was adopted 

 in 1910. J.M.F. 



Keokuk Dam, the largest powjr dam in the 

 world, extending across the Mississippi River 

 from Keokuk, Iowa, to Hamilton, 111. From 

 the fifteen turbine generators propelled by the 

 water which passes over it, electric power is 

 transmitted to Saint Louis, 145 miles away, 

 and to smaller cities in Illinois, Iowa and Mis- 

 souri. The turbine wheels, one of which 

 weighs sixty-five tons, or four times as much 

 as any ever before made, will eventually be 

 thirty in number, and together will produce 

 200,000 horse power. Each generator is able 

 to supply 9,000 kilowatts of electricity, enough 

 to light 225,000 lamps of the ordinary house- 

 hold type. Most hydroelectric generators are 

 operated at a speed of from 200 to 500 revolu- 

 tions per minute, but those at Keokuk are so 

 large that they turn fewer than sixty times a 

 minute. The amount of water which reaches 

 the turbine is controlled by a governor so 

 sensitive that the speed is changed even by 

 the starting of a street car in Saint Louis. 



The main part of the dam is 4,278 feet long. 

 It is set in the limestone bed of the river, and 

 is of concrete without reenforcement. In each 

 of the 119 arches through which the water flows 



is a steel gate which can be raised or lowered 

 to regulate the height of water-above the dam. 

 The lock through which river shipping passes 

 is the same width as those at Panama, but it 

 raises boats forty feet, eight feet more than 

 the largest Panama lock. 



Before the construction of the dam the river 

 for twelve miles above its site was navigable 

 only for a very short season each year, except 

 through a government canal with three locks. 

 Now there is a deep lake, and steamboats save 

 two hours in their passage up the Mississippi. 

 The dam was put in operation July 31, 1913, 

 after two and a half years of active work and 

 an equal amount of preliminary labor. It is 

 owned by a corporation the Mississippi River 

 Power Company. 



KEP'LER, JOHANN (1571-1630), a German 

 mathematician and astronomer, whose name 

 will endure in three imperishable principles of 

 astronomy known as Kepler's Laws, was born 

 at Weil, in Wiirttemberg, of poor parents. At 

 four years of age he recovered from smallpox, 

 which left him with crippled hands and im- 

 paired eyesight. He was educated at Maul-' 

 bronn and the University of Tubingen, and 

 was appointed to lecture on astronomy in 

 Gratz at the age of twenty-two. In that day 

 astronomers were chiefly employed in the con- 

 struction of almanacs that pertained to the 

 science of the stars, and Kepler set himself 

 about mastering the art. The great question 

 that he desired to answer was, how were the 

 great bodies in the solar system kept in their 

 position? He wrote a book on this subject 

 which brought him to the attention of Tycho 

 Brahe, who had him appointed as his assistant 

 in Prague. After Tycho's death, in 1601, a bril- 

 liant career was open to Kepler, as he was 

 appointed imperial astronomer and mathema- 

 tician. The laws that he discovered while in 

 this service became the foundation of as- 

 tronomy on more scientific lines. He passed 

 the latter part of his life at Linz, as professor 

 of mathematics. 



Kepler's Laws. Kepler left to the world 

 three astronomical laws, on which Newton's 

 discoveries of the attraction of gravitation 

 were founded; they became as well the basis 

 of the whole modern planetar. theory. These 

 laws are: 



(1) Every planet describes an ellipse, the sun 

 occupying one focus. See ELLIPSE. 



(2) The line joining the center of the sun with 

 the center of a planet sweeps over equal areas in 

 equal times. 



