TWENTY-FIFTH CONGEESS, 1837-1839. 151 



these different materials have hitherto been scarcely distinguished by their proper 

 names, even among our mariners and merchants. And the names, characters, and 

 habitudes of the plants which produce the textile fibers have, if possible, been less 

 clearly understood than the peculiar properties of the cordage itself. Thus the name 

 "sea grass" is sometimes applied to the fibers of a fleshy perennial plant of the 

 agave genus, which grows on dry, rocky hills, far in the interior of the country. The 

 influence of heat and moisture on all the different materials employed for either 

 cordage, sails, hammocks, bags, or clothing presents a wide field for useful research. 

 The relative strength and durability of tarred and white cordage has already engaged 

 attention in Europe, but further inquiries spring up as new materials are introduced. 



Not less important than either of the preceding topics is that of the strength and 

 other properties of iron, as applicable to the fabrication of chain cables and smaller 

 chains for standing or running rigging (the latter particularly for steam vessels), and 

 of bolts and anchors for all the various sea and river craft. Not only the strength 

 and elasticity but the chemical purity also of this material and its power to resist 

 corrosion are objects of deep interest. 



The naval and commercial marine interests are alike involved in an inquiry into 

 the possibility of obtaining an economical substitute for copper for the sheathing of 

 vessels, and whether that material itself may yet be defended from the corrosion 

 which now causes so heavy a charge on the Government as well as on the private 

 shipowner. A movable galvanic armature has been suggested for this purpose, but 

 awaits a trial of its efficacy. 



Other subjects of inquiry likewise press upon the attention, such as the most effi- 

 cient and economical forms of pumps and the best methods of working them; the 

 best modes of heating, ventilating, and disinfecting vessels at sea, and of freeing 

 them from vermin; of preserving every species of provision on long voyages; the 

 practicability of obtaining fresh water by any convenient apparatus for distillation 

 on shipboard; and the most effective means of securing ships from electrical dis- 

 charges. Time would fail us to enumerate all the beneficial results of an enlightened 

 application of science to the operations of dock yards, to the construction and use of 

 dry docks, screw docks, floating docks, and marine railways. 



To show that the importance of science to the naval interest is not herein overrated, 

 it may not be amiss to mention that a single division of science applicable to this 

 service of naval construction, that of the influence of form on the flotation and motion 

 of solid bodies in liquids, has not been thought unworthy to occupy the attention of 

 some of the ablest philosophers and experimenters of France, Sweden, and England. 

 The names of Bossut, of Lagherjelm, and of Beaufort are vouchers for the truth of 

 this assertion. The labor of the last-named author, in which it appears that hia 

 wife was a frequent participator, was truly herculean; and the splendid publication 

 and gratuitous distribution by their son of the thirty years' scientific labors of his 

 parents is a method of building a monument as novel and touching as it is liberal 

 and affectionate, while the monument itself is more honorable, perhaps, than any 

 which the pencils, burins, and chisels of Britain have ever produced. 



4. If from the public defense, both military and naval, we pass to the public rev- 

 enues, especially to that part which is derived from the sale of the public domain, 

 we readily find ample reason to sustain a call for scientific investigations. 



The agricultural value, the geological structure, the mineral resources, the botani- 

 cal productions, the supplies of water for manufacturing purposes, the true geo- 

 graphical position, and the force and present direction of terrestrial magnetism in the 

 regions where the public lands are situated are circumstances to be attentively 

 examined in prosecuting a survey of those lands. 



The analytical chemist will decide the value, for mining purposes, of those regions, 

 which the geologist and mineralogist shall have explored; while the engineer will 

 note whatever advantages and facilities may be offered for internal communications. 



The formation of a geological and [mineralogical collection would result, of course, 



