58 KANSAS CITY REVIEW OF SCIENCE. 
not yet annexed to the United States. California and New Mexico still belonged 
to Mexico. 
In Maps of Goodrich's history, 1853, Minnesota has a place north of Iowa 
with Missouri Territory and Indian Territory, as on Morse's Atlas. The north 
boundary of Oregon was 49°, and Utah included Nevada, and New Mexico in- 
cluded Arizona, and they were portions of the domain of the United States. 
On Mitchell's Map, 1864, the United States have their present boundary and 
all the States their present boundaries, but Idaho comprised all of the present 
Territory of Montana and part of Wyoming. Wyoming Territory did not as yet 
occupy a place upon our maps, but it has since been taken oif from portions of 
Dakota, Idaho and Nebraska. 
THE MINES OF OLD MEXICO. 
Pachuca, Real del Monte, El Chico and Santa Rosa, in the State of Hidalgo, 
are among the richest mining districts in the Republic of Mexico. Pachuca is 
the capital of the State, and lies fifty-seven miles north of the City of Mexico. 
The journey can be easily made by means of the Vera Cruz Railroad, with which 
Pachuca is connected by a tramway. As the tramway approaches Pachuca the 
mountains seem to draw near, one of them having on its summit a stone forma- 
tion which, in the distance bears a striking resemblance to a huge cathedral with 
domes and towers. It is in the region of this grand cathedral that some of the 
richest ores are found. 
It is obvious the advantage of this region over other districts in Mexico, be- 
ing thus easily connected v/ith the great capital and having easy access to the 
coast. That miners have availed themselves of this advantage is shown by the 
Hst of mines: Pachuca works 154, Real del Monte 76^ El Chico 24, Santa 
Rosa 13 — a total of 267. The powerful "Reab de Monte Mining Company" 
works 77 of these. Real Del Monte lies to the northeast of Pachuca, El Chico 
to the north, and Santa Rosa to the northwest. 
From the time of the conquest up to the present date it is estimated that these 
four districts have yielded $1,000,000,000 out of $4,000,000,000, the total 
amount extracted from the mines of Mexico. The Aztecs, before the conquest 
sought silver in these regions, and after the subjugation innumerable Spanish 
miners dug holes in the m.ountains, extracting what ore they could before their 
works were obstructed by water, when they abandoned them to dig other holes. 
The silver was obtained by smelting by the early miners, but it was in 1557 a 
Spaniard named Bartholeme de Medina discovered, in Pachuca, the process of 
amalgamation with mercury. His discovery is the basis of the "patio" process, 
which is the system most in use in Mexico, having been found, so far, the cheap- 
est and possibly the best adapted to the country. 
The ore when brought from the mine is cracked into small pieces and 
assorted according to its richness by hands employed for the purpose ; it is then 
