CHAPTER XVII 



SCIENCE AND INVENTION LANGLEY's 



AEROPLANE 



IN his laudation of the nineteenth century Alfred 

 Russel Wallace ventured to enumerate the chief in- 

 ventions of that period: (1) Railways; (2) steam 

 navigation; (3) electric telegraphs; (4) the tele- 

 phone; (5) friction matches; (6) gas-lighting; 

 (7) electric-lighting; (8) photography; (9) the 

 phonograph; (10) electric transmission of power; 

 (11) Rontgen rays; (12) spectrum analysis; (13) 

 anaesthetics; (14) antiseptic surgery. All preced- 

 ing centuries less glorious than the nineteenth 

 can claim but seven or eight capital inventions : 

 (1) Alphabetic writing; (2) Arabic numerals; (3) 

 the mariner's compass; (4) printing; (5) the tele- 

 scope; (6) the barometer and thermometer; (7) the 

 steam engine. Similarly, to the nineteenth century 

 thirteen important theoretical discoveries are as- 

 cribed, to the eighteenth only two, and to the 

 seventeenth five. 



Of course the very purpose of these lists namely, 

 to compare the achievements of one century with 

 those of other centuries inclines us to view each 

 invention as an isolated phenomenon, disregard- 

 ing its antecedents and its relation to contempo- 

 rary inventions. Studied in its development, steam 

 navigation is but an application of one kind of 

 steam engine, and, moreover, must be viewed as a 



