Masterpieces of Science 



him, he would construct an engine that should 

 satisfy their requirements, and prove itself capa- 

 ble of working heavy loads along the railway 

 with speed, regularity, and safety. At length, 

 influenced by his persistent earnestness not less 

 than by his arguments, the directors, at the sup- 

 gestion of Mr. Harrison, determined to offer a 

 prize of 500 for the best locomotive engine, 

 which, on a certain day, should be produced on 

 the railway, and perform certain specified con- 

 ditions in the most satisfactory manner.* 



The requirements of the directors as to speed 

 were not excessive. All that they asked for was 

 that ten miles an hour should be maintained. 

 Perhaps they had in mind the animadversions of 

 the Quarterly Review on the absurdity of travel- 



* The conditions were these: 



1. The engine must effectually consume its own smoke. 



2. The engine, if of six tons' weight, must be able to draw 

 after it, day by day, twenty tons' weight (including the 

 tender and water- tank) at ten miles an hour, with a pressure 

 of steam on the boiler not exceeding fifty pounds to the 

 square inch. 



3. The boiler must have two safety-valves, neither of 

 which must be fastened dowr, and one of them be com- 

 pletely out of the control of the engine-man. 



4. The engine and boiler must be supported on springs, 

 and rest on six wheels, the height of the whole not exceeding 

 fifteen feet to the top of the chimney. 



5. The engine, with water, must not weigh more than 

 six tons; but an engine of less weight would be preferred 

 on its drawing a proportionate load behind it; if of only 

 four and a half tons, then it might be put on only four wheels. 



The company will be at liberty to test the boiler, etc., by a 

 pressure of one hundred and fifty pounds to the square inch. 



166 



