POITLMI SCIENCE MO XT JILT 



475 



THE PROGKESS OF SCIENCE. 



JOffiY ERICSSON. 



The centenary of the birth of John 

 Ericsson was celebrated on August 1 

 by the unveiling of a statue in the 

 Battery, New York City. A bronze 

 statue by Mr. Jonathan S. Hartley 

 had for ten years stood near the Cus- 

 tom House, but the sculptor wished to 

 improve it, and at his own expense 

 made a new statue, in wliich the same 

 metal was used. By the courtesy of 

 Mr. Hartley, we reproduce a photo- 

 graph of the model as it stood in his 

 studio. The ceremonies connected with 

 the imveiling of the statue were elab- 

 orate, the army and navy being repre- 

 sented, and the Swedish-American So- 

 cieties taking a prominent part. Mayor 

 Low accepted the statue for the city 

 and Colonel W. C. Church, author of 

 the life of Ericsson, made an address. 

 Both speakers naturally referred to the 

 building of the Monitor and its destruc- 

 tion of the confederate ironclad Mer- 

 rimac on March 9, 1862. It will be 

 remembered that on the preceding day 

 the Merrimac had destroyed the Cum- 

 ierland and the Congress, and was 

 about to disperse the rest of the gov- 

 ernment's wooden fleet, when the Mon- 

 itor, which had been l)uilt by Erics- 

 son in New York in one hundred days, 

 altered the course of events and per- 

 haps the whole result of the civil war, 

 for if the federal government had had 

 no fleet, European intervention would 

 have been likely. Shortly after Erics- 

 son came to the United States in 1839, 

 he built the Princeton for the United 

 States Na\'y, the first vessel having the 

 propelling machinery below the water 

 line, and this vessel set the model for 

 all subsequent naval construction. 

 Ericsson is consequently remembered 



largely in connection with the develop- 

 ment of ships of war. to which he made 

 the most important contributions. 

 His other gi-eat scientific inventions, 

 however, should not be forgotten, es- 

 pecially the screw propeller, which 

 while originally designed for warships 

 has become one of the greatest factors 

 in steam navigation. Europe was long 

 sceptical as to the possibility of the 

 propeller, it being claimed that a ves- 

 sel would not steer when power was 

 applied at the stern, even after many 

 vessels were being successfully navi- 

 gated in the United States. 



Ericsson began his inventions when 

 a boy in Sweden, and at the age of 

 twenty-two constructed a condensing 

 flame engine of ten horse power. In 

 1828, when twenty-five years of age, 

 he made the first application to navi- 

 gation of the principle of condensing 

 steam and returning water to the 

 boiler. In 1829, when twenty-six years 

 old, he built the steam carriage, 

 Xovcify, which competed with George 

 Stevenson's for the Liverpool and Man- 

 chester railway prize. It surpassed all 

 competitors, including Stevenson's 

 Rocket, in lightness and speed, attain- 

 ing the remarkable speed of thirty 

 miles an hour. At this period and a 

 little later he made numerous impor- 

 tant inventions, including the tubular 

 steam boiler with artificial draught and 

 the caloric heat engine. He also made 

 some important instruments for scien- 

 tific work, including the self-registering 

 deep-sea lead, a pyrometer and a 

 hydrostatic gauge. Ericsson must be 

 regarded as one of those who made the 

 nineteenth century before all else an 

 era of the applications of science. 



