FRAGMENTS OF SCIENCE. 



285 



the time muzzled, but in many instances with 

 growl barely suppressed. In a rough-and- 

 ready way one may estimate the cost of this 

 fleet of one hundred great armor-clad ships 

 of war, with twenty-five lesser vessels, at ap- 

 proximately $200,000,000, which is probably 

 four or five times the cost of the peaceful 

 water-way, the opening of which they were 

 called together to celebrate. The United 

 States was represented by one battle ship 

 and, I believe, by one of our two ' commerce- 

 destroyers,' so called. The two armored 

 ships so named cost nearly $7,000,000 a 

 sum nearly equal to the entire endowment of 

 Harvard University while the annual ex- 

 pense of keeping the two in commission is 

 nearly as great as the pay roll of the same 

 university. The only commerce of any im- 

 portance upon which these destructive ships 

 of war could exert their force would be that 

 of Great Britain and Germany, our two largest 

 foreign customers for the excess of our farm 

 products, which would rot upon our fields 

 if we could not sell them for export. Any 

 commentary upon these grotesque conditions 

 would perhaps be superfluous. As time goes 

 on this waste of preparation for war will be 

 stopped in more than one way. First, be- 

 cause no ship can carry armor which will de- 

 fend it from the latest type of guns. Next, 

 because no land force can stand in the face 

 of guns discharging over six hundred shots 

 per minute, warranted to kill at more than a 

 mile. But lastly, as to European states, be- 

 cause the limit of taxation has been reached. 

 New taxes can not be invented and new 

 sources of revenue can not be discovered 

 which will warrant even the maintenance of 

 existing armies and navies." 



Two Wild Vegetables of Merit. T. W. 



Card, of the experiment station at Lincohi, 

 Nebraska, calls attention, in Garden and 

 Forest, to two wild vegetables which he 

 thinks merit the attention of cultivators. 



One of these, which is already gathered 

 from the fields and used to a considerable 

 extent in the West, is the wild lettuce ; there 

 are two species common on the plains, Lac- 

 tuca canadensis and L. Ludoviciana. They 

 are chiefly used for greens, and fill an im- 

 portant place for this purpose, as they come 

 in advance of spinach, and when no other 

 greens are offered in the market. The other 



plant is the ground plum or bulfalo pea of 

 the plains (Astragalus cransicarjjus). This is 

 found abundantly in the draws or low 

 grounds of the unbroken prairie. The 

 plant is a perennial, apparently perfectly 

 hardy, and very productive. The fruit re- 

 sembles gooseberries in size and general 

 appearance. It is borne in numerous clus- 

 ters, very early in the season. When cooked 

 like string beans the fruit forms a very ac- 

 ceptable dish. The chief point which recom- 

 mends the plant for cultivation is the time 

 at which the fruits are ready for use, some 

 of them ripening as early as May 7th. 



Protecting Iron and Steel against Rnst. 



Gesner's method, described in La Revue 

 Scientifiqne, consists in forming on the sur- 

 face of the metal a double carbide of hydro- 

 gen and iron. A bar thus coated can be 

 bent through an angle of forty-five degrees 

 without disturbing the layer. The process 

 is as follows : The surface to be coated is 

 first thoroughly cleaned from rust. A couple 

 of gas retorts are placed alongside each other 

 and raised to a temperature of from 600 

 to 700 C. The articles to be treated are 

 then placed in these retorts for about twenty 

 minutes, after which a current of hydrogen 

 is passed through the retorts for forty-five 

 minutes. A small quantity of naphtha is 

 then introduced, the supply being main- 

 tained for ten minutes. It is then stopped, 

 the current of hydrogen being kept up fif- 

 teen minutes longer, when it is stopped and 

 the retorts are allowed to cool to 400 C., 

 and when this temperature is reached the 

 doors can be opened and the finished prod- 

 uct removed. The coating thus given has a 

 bluish color. 



Tlie Microscope in Metallurgy. Micro- 

 metallography the examination of samples 

 of iron and steel by looking at etched or 

 polished sections through a microscope is 

 rapidly taking its place in the routine work 

 of metallurgical laboratories. It has been 

 developed from petrography. Dr. Sorby, an 

 Englishman, who in 1864 submitted some 

 photographs of opaque sections of various 

 kinds of iron and steel to the British Asso- 

 ciation, seems to have been among the first 

 workers in this field. The process of pre- 

 paring the specimens is complicated and 



