330 BULLETIN OF THE 



tant human populations — liave been sporadic as it were, and 

 their prevalence comparatively transitory. "It appears there- 

 fore tliat civilization itself may be considered as a condition of 

 unstable equilibrium, which requires constant effort to be sus- 

 tained, and a still greater effort to be advanced. It is not in 

 my view the 'manifest destiny' of humanity to improve by the 

 operation of an inevitable necessar}' law of progress: but while 

 I believe that it is the design of Providence that man should be 

 improved, this improvement must be the result of individual 

 effort, or of the combined effort of many individuals animated 

 by the same feeling and co-operating for the attainment of the 

 same end. ... If we sow judiciously in the present, the 

 world will assuredly reap a beneficent harvest in the future : 

 and he has not lived in vain, who leaves behind him as his 

 successor, a child better educated — morally, intellectually, and 

 physically, than himself. From this point of view, the respon- 

 sibilities of life are immense. Every individual by his example 

 and precept, whether intentionally or otherwise, does aid or 

 oppose this important work, and leaves an impress of character 

 upon the succeeding age, which is to mould its destiny for weal 

 or woe, in all coming time. . . . The world however is 

 not to be advanced by the mere application of truths already 

 known : but we look forward (particularly in physical science) 

 to the effect of the development of new principles. We have 

 scarcely as yet read more than the title-page and preface of the 

 great volume of nature, and what we do k;iow is as nothing in 

 comparison with that which may be yet unfolded and applied."* 



Experiments on Building-stone. — In 1854, a series of experi- 

 ments on the strength of different kinds of building-stone, was 

 undertaken by Henry as one of a commission appointed by the 

 I'resident, having reference to the marbles offered for the exten- 

 sion of the United States Capitol. Specimens of the different 

 samples — accurately cut to cubical blocks one inch and a half 

 in height, were first tried by interposing a thin sheet of load at 

 top and bottom, between the block and the steel plates of the 



■* Proceed. Assoc. Adv. Education, 4th Session, Wasliington. Dec. 28, 

 1S.54, pp. 17-3'. The pregnant thought that huiiiau civilization is an 

 artificial and coerced condition, would seem to have a suggestive t>earing 

 on tlie two great theories of development and evolution, so generally con- 

 Inunded by tlie superficial. Wliat may be called tlie radical diffeience 

 1 etween these two views of organic extension, is that the former assumes 

 {tn inherent mysterious tendency to progression, whose motto is ever 

 '•excelsior;" while the latter assumes a general tendency to variation 

 within moderate limit* in indefinite directions; so that elevation is 

 no more normal than degradation, and indeed may be re^^arded as rarer 

 and more exceptional, sime at every upward stage attained by the few, 

 there are probably more further dii.'ressions dowuwar I tliau upward, the 

 iiiolto being ever '"aptiur.'' 



104 



