A system of leasing portions of mining claims, called “chloriding” in Calico, was introduced in the early days, and is still in vogue. Many poor men have made moderate fortunes in the district, and in days gone by all did well. The mines are leased on a royalty of one fourth to one sixth of the ore to the claim owner, according to its value, the owner receiving more as the grade is higher. Chloriders were at work on the Loo, Little Waterman, Humbug, Bismarck, Blackfoot, and other mines, during the past year. The ore obtained in this manner is usually sacked and shipped to a custom mill, where it is crushed, the charges ranging from $9 to $12, according to the character of the ore, some (the more brittle) milling much faster than others. THE WATERLOO MINE. The Waterloo property consists of four claims. The principal workings are in the Waterloo Mine, where large stopes have been extracted, though considerable amounts of ore still remain in sight. An idea of the extent of some of these Calico mines may be gained from the fact that the great ore body of the Waterloo is 1,100 feet in length, and is known to extend from the surface down to the 525-foot level. At the east end the ore-bearing zone is from 4 to 7 feet in width, widening downward. Going westward it increases in width until it is 60 to 70 feet wide. This mine, like those immediately about Calico, was worked for rich pockets, and, as a natural consequence, the mine was left in bad condition. Jos. D. Kerbaugh, the last Superintendent of the mine, had inaugurated a systematic method of extracting ore and recovered much lost ground. The ore is usually low grade, and this, in connection with the low price of silver, has resulted in the closing up of the mines. A narrow gauge railroad has been in use for several years to transport the ore from the Waterloo group and the King and Red Jacket Mines, owned by the same company, to their mills at Daggett, timber and supplies being brought to the mines on the return trips. The transportation of ore, I was informed, cost 12 cents per ton. The railroad is about 7 miles in length, and runs on a pretty steep grade. THE BORAX MINE. In the upturned sedimentary beds which flank the Calico Hills, dipping outward toward the desert plain on all sides of the uplift, except where purely local disturbances have caused a reverse condition, are bedded deposits of calcium borate and gypsum (calcium sulphate). Five miles east of the town of Calico is the largest known deposit of calcium borate in the district. The bed, or vein, as it is called, was discovered some years since, and finally passed into the hands of the present owners, the Pacific Coast Borax Company, whose extensive works are located at Alameda, near San Francisco. GEOLOGY OF THE BORAX DISTRICT.