322 ANNUAL OF SCIENTIFIC DISCOVERY. 



trinsic value at the outset of their careers. So long as they re- 

 tain the marks of the mint dies, however faintly defined, they are 

 permitted to circulate, and hence they in some cases lose one-third 

 of their substance before being withdrawn and remodelled. 



To cover the constantly recurring waste of money by attrition, 

 a sum of money averaging that mentioned above is set apart year 

 by year, and it is said that it scarcely suffices for the purpose. If 

 it be asked, " What becomes of the products of attrition, the par- 

 ticles of silver and gold daily detached from our coinage ? " that 

 is a question which we cannot solve. The precious metals are in- 

 destructible, and there must of necessity be a very large quantity 

 in invisible existence in England at present. Probably samples 

 of dust taken from the thoroughfares of the metropolis, if an- 

 alyzed carefully, would }neld a small percentage. 



It has been estimated approximately that in 3 years of ac- 

 tive circulation crown pieces lose 5 per cent, of their original 

 weight, half-crown pieces 10 per cent., shillings 30 per cent., six- 

 pences 40 per cent., and threepences 42 per cent. Bronze coins 

 are made of sterner stuff than standard silver, and their rates of 

 deterioration no doubt will be proportionally less. The penny is 

 an actively circulated piece of money, while the farthing is very 

 idle. It is likely, therefore, that the larger coins in this instance 

 will first break down, and thus invert the law as to silver. Much 

 would be done in the way of mitigating the loss by wear if all 

 coins were furnished at their birth with broad and deep projecting 

 rims. These would then bear the brunt of attrition and save the 

 obverse and reverse impressions of coins from that speedy deface- 

 ment which awaits their appearance in public. The Engineer. 



STATISTICAL SUMMARY. 



Wages in Great Britain. By the annexed paragraph, from a 

 London newspaper, it appears that the average rate of wages in 

 England and Ireland is higher than we are wont to suppose, fully 

 justifying Mr. Bright's statement that the price of labor has risen 

 25 or 50 per cent, within the last 30 years. Reduced to our pres- 

 ent currency, the daily wages are, in England, 1.50; in Scotland, 

 1.37; and in Ireland, 0.96. This allows 40 cents to the shilling, 

 which is less than the rate of exchange to-day. 



" It appears from an elaborate return, prepared by Mr. Leone 

 Levi, in conjunction with Mr. Bass, M. P., that there are 10,697,- 

 000 working people in the United Kingdom between 20 and 60 

 years of age, and that their total earnings amount to 418,300,000 

 pounds sterling per annum, distributed as follows : England, 311,- 

 500,000 pounds; Scotland, 42,700,000; Ireland, 64,100,000. This 

 gives an average weekly income of 22s. 6d. in England, 20s. 6d. 

 in Scotland, and 14s. 4d. in Ireland." 



Density of Population. In the year 1865, Belgium had 365 in- 

 habitants to the square mile, England and Wales had 367, and 

 France 176. If the United States was as densely populated as 

 France, our population would amount to 528,000,000; as England 

 and Wales, 924,000,000 ; and, according to the Belgium density 



