556 The Smithsonian Institution 



whom even now, a generation later, road-building has hardly 

 passed the temporary stage. 



Important technical papers are printed in the Smithsonian 

 Report for 1864, including an extract from the memoir on 

 the " Preservation of Copper and Iron in Salt Water," by 

 Becquerel, the translation of which was furnished by Admiral 

 C. H. Davis, then Chief of the Bureau of Navigation of the 

 Navy Department. This is followed by an equally impor- 

 tant paper on the preservation of wood, in which the principal 

 mechanical and chemical methods of treatment are discussed. 

 There is also an interesting paper on " Caoutchouc and Gutta- 

 percha," and also one on the " Products of the Combustion 

 of Gun-cotton and Gun-powder," thus illustrating the mar- 

 velous parallel growth of the arts of peace and of war in the 

 United States during these years. In the Report for 1870 

 there is an almost prophetic letter by Henry, to an unknown 

 correspondent, in reference to the character and importance 

 of a "physical observatory." He refers to his interest in the 

 examination of several European institutions of this class 

 during a recent visit abroad, of the very interesting and im- 

 portant work which they may accomplish, and gives some 

 excellent advice as to their organization and management. 

 There is one sentence which cannot be too frequently quoted, 

 in which he says, " It is, therefore, in the highest degree in- 

 judicious in the founding of an establishment to exhaust the 

 source of its power by architectural display not absolutely 

 required, and which may forever involve a continual expense 

 from the remaining funds to keep them in repair." He speaks 

 of finding in England " observations which have challenged 

 the admiration of the world," carried on in a temporary 

 structure made of rough boards, unplastered, and hardly more 

 than fifteen feet square. This condition of things the Institu- 

 tion has itself practically repeated after a score of years. 



