JOSEPH HENRY. 365 



of nature. But, more than any discovery, it makes science respected 

 in high places, and enlists the sympathy of the unscientific community. 

 There are times when sextants, chronometers, tables of the moon, and 

 even light-houses, are of no avail, and an impenetrable veil of dark- 

 ness shuts out the mariner from the lights of heaven and earth. But 

 what is opaque to light may be pierced by sound. The experiments 

 which have been made by Henry in this country and by Tyudall in 

 England, in their official capacity, on the fog-penetrating power of the 

 fog-horn, the fog-bell, the siren, the steam-whistle, and cannonading, have 

 raised interesting questions in science, to which different answers have 

 been given ; but the facts remain, above controversy, to instruct gov- 

 ernments in the best way of supplementing optical signals by acoustic 

 signals. These last investigations of Professor Henry, to which, it is 

 feared, he was a willing martyr, will always have a pathetic interest for 

 those who knew and loved him. 



It has been the aim of this notice to place in strong relief a few of 

 the salient points in the intellectual life of Henry. Any statement in 

 detail of the accumulations of his long life, in the way of experiment 

 or deduction, must be very voluminous or very meagre. For he was 

 not a concentrated specialist. His expanded thought swept the whole 

 vast horizon of the physical sciences ; not to speculate, but to discover. 

 The severe discipline of science did not harden him against the fasci- 

 nations of literature, poetry, and art. 



It would be a delicate task, and premature, to attempt to assign to 

 Henry his exact rank among those who have legislated for science in 

 this and former centuries. There are laws of perspective in time as 

 well as in space, whereby a small eminence seems to outclimb the 

 distant Alps, and the present generation dwarfs apparently all its pre- 

 decessors. Foreign countries and posterity will pronounce their irre- 

 versible verdict in this as in other cases. In his own country, and 

 among his contemporaries, Mr. Henry was long and easily the acknowl- 

 edged chief of experimental philosophers. If the earlier science 

 of the country is passed in review, only a few names shine so brightly 

 across the intervening years as to deserve any comparison with him 

 who has recently departed. Winthrop and Rittenhouse in astronomy, 

 Franklin in electricity, Rumford in thermotics, and Bowditch in mathe- 

 matics, exhaust the catalogue of possible rivals. Of these, all but 

 Winthrop were self-instructed, as was Henry, at least in what relates 

 to their higher education. Of these, Franklin and Rumford, no less 

 than Henry, were as remarkable in administration as in science ; 

 Franklin and Rumford from taste, and Henry from a sense of duty. 



