Kansas Academy of Science. 13 



absoliite velocity of light, knowing which, and the time occupied by light in coming to 

 us from the sun, the distance of the sun becomes determinable. 



The value of this method of determining the solar parallax will depend upon the pre- 

 cision of the lunar tables, but, with the elimination of the effects of the error above 

 explained, it is possible such pi'ecision may be attained as shall make the method 

 valuable. 



The comparative frequency of eclipses would enable astronomers to accumulate obser- 

 vations rapidly, and the more rapidly reduce the degree of error. 



POSTSCRIPT. 



The foregoing remains the same as originally prepared, though from further inquiry it 

 appears that in the case of the lunar and solar eclipses ajyparent instead of true geocentric 

 opposition and conjunction are understood in the elements given in tlie Nautical Almanac 

 for those computations, so that no error in the moon's place could thus occur. A similar 

 remark applies in the case of the transit of Venus. 



The fact of the lagging of planetary shadows, seems, however, to deserve recognition, 

 though it furnishes no aid in the attempt to diminish the discrepancies between lunar 

 theory and observation. And though these discrepancies are still so great as to indicate 

 a specific cause which has so far eluded discovery, it is yet reasonable to believe that the 

 true cause lies within the operations of known law; that this cause will ultimately be 

 found out, when the moon will appear to move completely subject to the law of gravita- 

 tion, and will conform gracefully to the predictions of astronomers. 



Lawrence, Kansas, December 7, 1874. 



ON TIN "SALTING" ENTERPRISES IN THE UNITED STATES. 



BY PROF. WM. K. KEDZIE. 



Among the many elements whicii enter into, and add to the completeness of what we 

 in egotistic phraseology term "our modern civilization," there are many most vitally im- 

 portant in their relations to the wants and necessities of civilized life, for which modern 

 civilization is in no way responsible. They are the product, not of modern enterprise or 

 industry : on the contrary, they are an inheritance, handed down to us from a remote 

 and barbaric past. 



Not the least important in its multitudinous and vital relations to tlie usages of civilized 

 life, and for which we here to-day are mutually debtors to p-e-civilized enterprise, may 

 lae mentioned the metal, tin. The mere mention of the metal calls up before us the 

 thousand-and-one uses and purposes which it subserves in every-day life. Whether in 

 the form of block-tin, or as a coating to inferior but more durable metals, such as iron or 

 copper, or in the beautifully semi-crystalized condition known as moiree metallique, or in 

 the form of foil of one one-thousandth of an inch in thickness — so indispensable in the 

 manufacture of mirrors; its brightness and beauty, almost equaling that of silver; its 

 durability in air at ordinary temperatures — all conspire to render- it a metal of incalcu- 

 lable value in the manufacture of articles of ornament and of every-day use. 



And yet indispensable as we in this age and country have learned to regard this metal, 

 it is interesting and instructive to note how little actual progress in the mining and metal- 

 lurgy of tin has been made in the last three thousand years. For by this you will see 

 that I place the discovery and first manufacture of tin from its ores, at a point far antedating 

 the birth of the Christian era. No learned savant in the old world of alchemy has been 

 able to hand his name down to posterity, linked with so all-important a discovery. 



