EULOGY ON PROFESSOR ALEXANDER DALLAS BACHE. 361 



orous existence, was well calculated to exhibit his talents and develop 

 his character. It brought him into intimate association with the prin- 

 cipal manufacturers, engineers, and artisans of the city, and into 

 relations of friendship with a large number of young men destined, in 

 more advanced life, to exert an extended influence on public affairs. 

 He was appointed chairman of one of the most important of its com- 

 mittees, and was chosen as the expounder of the principles of the insti- 

 tute at its public exhibitions. Facilities were thus afforded him for the 

 prosecution of science, which he could not have well commanded in any 

 other position. Workshops were thrown open to him, and skillful hands 

 yielded him ready assistance in realizing the conceptions of his suggest- 

 ive mind. His descent from the illustrious statesman and philosopher 

 whose name the institute bears, and who is almost regarded as the tute- 

 lar saint of Philadelphia, no doubt contributed to a prepossession in his 

 favor, but the influence which he acquired and maintained was due to 

 his own learning, industry, ability, and courtesy. To these he owed the 

 favor and distinction of having conferred upon him the principal direct- 

 orship of the scientific investigations of the institute, and the opportu- 

 nity which it afforded him of so greatly contributing to the usefulness 

 of the society and to the advancement of his own reputation. 



For a full account of the labors in which he was engaged in his con- 

 nection with the Franklin Institute we must here be content with refer- 

 ring to the volumes of its journal from 1828 to 1835 inclusive. We may 

 pause a moment, however, to notice the investigations relating to the 

 bursting of steam-boilers, of which he was the principal director. The 

 public mind had, at that epoch, been so frequently and painfully called 

 to this subject that the institute was induced to organize a series of 

 systematic researches in regard to it, the importance of which was soon 

 recognized by the General Government in the form of an appropriation 

 for defraying the attendant expenses. In the prosecution of these 

 inquiries a large amount of information relative to explosions, and sug- 

 gestions as to their causes, was first collected by correspondence, and on 

 this was based a series of well-devised experiments, which were exe- 

 cuted with signal address, and the results interpreted with logical dis- 

 crimination. The conclusions arrived at were embodied in a series of 

 propositions, which, after a lapse of more than thirty years, have not 

 been superseded by any others of more practical value. The most fre- 

 quent cause of explosion was found to be the gradual heating of the 

 boiler beyond its power of resistance ; and next to this, the sudden gen- 

 eration of steam by allowing the water to become too low, and its sub- 

 sequent contact with the overheated metal of the sides and other 

 portions of the boiler. The generation of gas from the decomposition 

 of water as a cause of explosion was disproved, as was also the disper- 

 sion of water in the form of spray through superheated steam. These 

 experiments were not unattended with danger, and required, in their 

 execution, no small amount of personal courage. Accidents were irnini 



