40 KANSAS CITY REVIEW OF SCIENCE. 



nurseries for trees, with an area of 6^ acres. The qualities sought in such trees 

 are {a) rapid growth, (i^) shade, (<:) non-liability to attack by insects; and the 

 trees selected on these grounds are chestnut, elm, the western plane, lime, and 

 maple. One hundred and fifteen men are employed attending to the trees. The 

 seats in streets and squares number three hundred. 



Sewage. — We visited the great sewer in the Rue de la Pepiniere, being met 

 there by the officers of the municipality, detailed by order of M. Bufiflers. This 

 sewer was lighted up by means of fifty-six moderator lamps. The man in attend, 

 ance showed the apparatus for pushing along sand and mud deposited on the 

 bottom of the sewer. The sewer first inspected was of the second class. The 

 water pipes and gas pipes are attached to the crown or sides of the sewers, thus 

 avoiding tearing up the roadway when pipes need repairing. A truck, with pad- 

 dle board moved by the current, is used to force along the sand and mud. We 

 next visited the main sewer, or collector of all sewage coming from the right bank 

 of the Seine. The mean velocity in the collector was 165 feet per minute. The 

 sewers received (i) large portions of street sweepings; (2) storm water; (3) 

 water thrown out from houses; (4) contents of water closets; (5) urine from 

 closets fitted with double cylinder. From five hundred to six hundred men are 

 employed in the sewers, of whom thirty-two work in the great collector. The 

 length of this main sewer is seven and a half miles, the length of main on the left 

 bank of river, five miles, and the total length of sewers in the city is five hundred 

 miles. The daily outfall of all sewers is 300,000 cubic meters, or 66,000,000 

 gallons. — Van Nostrand's Eng. Magazine. 



MINERALOGY AND METALLURGY. 



THE MINES OF MEXICO. 



Some years ago I went from White Pine to Mexico. As I passed Eureka (or 

 where it now stands), Stetefeldt told me to stay, since Eureka would be the big 

 camp of the coast. His prediction has been amply verified. My first visit to 

 Mexico lasted five years and three months. I served as superintendent of three of 

 the large mines (mentioned by Ward and Humboldt) ; I visited some of the cele- 

 brated old mining districts ; and so was enabled to form something of an opinion. 



The first idea of the gringos, or Americans in Mexico, is annexation to the 

 United States. They are constantly urging it, and often make much trouble for 

 themselves thereby. Our people are energetic, and rush ahead ; but in so doing, 

 they respect the rights of no one. They damn the country, the religion, the 

 "grub," the law and the cHmate — everything. 



The Mexicans do not forget the lesson taught them in Cahfornia in 1849 ^.nd 

 1850. They well remember how they were rooted out of California, Arizona, 



