Company on 80 acres adjoining the Harker Mine on the north. This company also has a lease on the magnesite deposits on the Gill ranch adjoining the Oakland ground on the north. The first three groups adjoin and are in the Success district 7 miles east of Porterville. The Oakland-Gill groups are on the north of Porterville Hill 3 to 4 miles northeast from the railroad station at Porterville. At present, mining operations are confined mainly to the "Tulare' ground, and portions of the 'Lindsay' and the 'Gill Lease' properties, the last-named being worked under a contract by Ed. Cramer. All calcining is done in rotary furnaces at their plant in Porterville (formerly American Refractories Company; also American Magnesite Company a subsidiary of International Magnesite Company). Ore from the Success district is brought in by rail over the branch line of the Southern Pacific Company, and from the others by motor truck.

The National Kellastone Company, of which the Sierra Magnesite Company is an associate (being controlled by the same financial interests), has one of its stucco plants here, where stucco mixtures are prepared for sale to contractors and material dealers. All of the technical control work of the National Kellastone Company is carried on at Porterville in the physical-test and chemical laboratories. Both of these laboratories are especially and completely equipped for such work. Because of the high summer temperatures, there is a below-ground basement room under the physical-testing building for use in the summer months, so that fairly uniform temperatures may be had for testing throughout the year.

Because of their careful technical control a uniform product of guaranteed behavior can be delivered. Their three commercial grades, with approximate chemical analyses are as follows (it being understood that the guaranteed physical tests are of more vital concern than a specific chemical composition):

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'Sierra Standard.' White or light gray color when ground; MgO 83%-85%; CaO (under 4% total; 1.5% active); Al,O, & Fe,O, under 1%; SiO, up to 8%. Ignition loss 2%. Used for finish-coat stucco. "Tulare A.' Cream color; MgO 85%-87%; Al2O, & Fе,03 3%; CaO (3% total, 11% active); SiO, 5%-6%. Ignition loss 3%. For flooring finish coat; also some for stucco.

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'No. 20' or 'Base Coat' (also called 'No. 20 B.C.'). Color varies, dark cream, light brown, etc. MgO 80%; CaO 3%; Al1⁄2О, & Fe ̧0 ̧ about 4%; SiO1⁄2 12%-14%. Ignition loss 4%. For base coats, both in stucco and floors.

Fine grinding of the calcined material, in preparation for stucco and plaster mixtures, is accomplished in 12 buhr mills in two banks, so that 85% will pass 200 mesh.

In November, 1923, there were 75 men employed in the mine, and a total of 49 in the plant, laboratories, and office, including 9 in the National Kellastone unit.

OTHER NON-METALLIC MINERALS.

An effort to increase the use of agricultural limestone, gypsum and other so-called mineral fertilizers is evident, and among the new operators in this district are the Mt. Diablo Lime and Marl Co., Walnut Creek, Contra Costa County, and the Mission Lime Marl Co., of Irvington, Alameda Co.

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Various colored rocks, when crushed and sized, are used as a 'dash' coat on stucco for exterior finish and for roofing. There is a good demand for hard, bright-colored material. Obsidian was produced for this new use during 1923, the production coming from near St. Helena, Napa County.

The foundry men of America have raised a fund for carrying on detailed tests and research work on samples of sand which are being used or which may be thought suitable for foundry molding use. The tests are being made under the supervision of the Engineering Division of the National Research Council, with the cooperation of State Geologists and the U. S. Geological Survey.

In order that the producers and users of molding sand in California might benefit from this investigation, the State Mining Bureau has cooperated to the extent of collecting samples from all known deposits and reporting upon their character, size, method of working, ownership, etc.

Samples from two producers in the San Francisco field division were procured and included in the total of twelve samples sent from this State. These two were from the deposit of the Del Monte Properties Company, near Carmel, Monterey County, and from the George Small deposit, on the Alameda Creek road, near Decoto, Alameda County. The Del Monte Properties Company produce sand for a variety of uses, but the George Small deposit is strictly molding sand.

A new plant for the recovery and production of various magnesium salts from the bitterns remaining after the precipitation of common salt from sea water was completed in 1923 by the Industrial Chemical Corporation, and is now in operation. The plant is located on the property of the Arden Salt Works near Newark, Alameda County; the bitterns from the Arden Salt Works being taken under contract. E. M. Vail is manager, Newark, California.

Much of the San Francisco division engineer's time is taken up in routine office duties and in replying to written and verbal requests for information relative to all phases of the Mining industry.

After the discontinuance of the monthly publication of 'Mining in California' in April, the service formerly offered 'Producers and Consumers' in this publication was continued by issuing a monthly mimeographed list of current inquiries for deposits and tonnages of minerals 'wanted' and 'for sale,' under the title of Commercial Mineral Notes. Apparently these lists have been of considerable value to those looking for a source of supply and to prospective producers seeking a market, as the State Mining Bureau has been advised of a number of transactions closed through its aid, or under negotiation.

It has also been noted that these listings are closely watched by many large and responsible firms, who form an increasing percentage of those investigating offers. Requests for various minerals come from the manufacturing centers in the eastern states, a few from foreign countries, and many from local firms and individuals. Only deposits in California, or tonnages originating therein, are intended to be listed for sale.

During the year 303 parties seeking a market were listed; there being 88 different products offered by them, and 152 separate 'wants' were listed, which included requests for 102 different mineral products. The larger part of the 'wants' was for non-metallic minerals of the

structural, industrial, fuel and saline groups, with a lesser number of inquiries for gold and other metal mines.

Inquiries for arsenic ores, clay, magnesite, coal, manganese, limestone, montmorrillonite, quicksilver, sillimanite, andalusite and cyanite were comparatively frequent. Other minerals wanted included zeolite, lepidolite, gilsonite, flint, epidote, beryl, amblygonite, alunogen, asbestos, molybdenite, jasper, as well as the more common minerals.

With very few exceptions, all of the minerals wanted are known to occur in the State, but as yet some of them have not been found in commercial quantities. In many cases this may be due to lack of knowledge of the valuable non-metallics on the part of prospectors. Sillimanite, for which there is a keen demand, would scarcely attract the attention of one not especially searching for it, as much of it resembles an ordinary worthless rock. The only deposit so far being mined in the United States is in Mono County, California, but it is quite certain that other deposits of commercial size will be found, and, if so, they should prove valuable to the discoverers. Sillimanite is used in the manufacture of high-temperature and high-tension electrical insulators and spark plugs. That produced here at present is being shipped to Detroit, Michigan. It is worth about $.05 per pound, or $100 per ton, as mined.

Imperial County.

LOS ANGELES FIELD DIVISION.

W. B. TUCKER, Mining Engineer.

Shipments of pumice are being made from a deposit owned by J. H. When, G. E. Miller, and D. S. Underwood of Niland. The deposit is located near Niland, and it is reported that during the month of August, 1923, seven cars were shipped to Chicago.

Inyo County.

CERRO GORDO DISTRICT.

The Cerro Gordo Mines Company reports that a new ore body, carrying high grade silver values, has been encountered at a depth of 1000 feet in the old Union Mine. The vein is said to have a width of four feet.

Queen of Sheba Group of Mines, consists of nine claims located in the eastern slope of the Panamint Range of mountains, about 40 miles northeast of Zabriskie, a station on the Tonopah and Tidewater Railroad.

Owners: New Southerland Divide Mining Company, of San Francisco. The property has recently been leased to the United States Smelting Refining and Mining Company; main office, 55 Congress Street, Boston, Mass.

The ore occurs as replacement ore bodies in limestone and is rich in galena, lead carbonates and silver sulphides. The ore is said to average 15 per cent lead, and 8 ozs. of silver per ton. It is stated that 6500 tons of sorted ore shipped to the smelter near Salt Lake City averaged 40 per cent lead and 20 ozs. in silver per ton.

It is reported that the United States Smelting, Refining and Mining Company expect to start mining operations at an early date.

Kern County.

COVE MINING DISTRICT.

The Cove Mining District is situated 42 miles north of Caliente, near the town of Kernville. The mines are at an elevation of 2600 to 3000 feet above sea level in the foot hills of the High Sierras. The district is connected by a good mountain road with Caliente, on the Southern Pacific Railroad, which is the nearest railroad point.

History: The first discovery of gold in this region was made by a member of General Fremont's party in 1851, in Greenhorn Gulch. In 1861, Rogers and Old discovered gold on what is known as the Beauregard vein, near Kernville. The discovery of the Beauregard, Jeff Davis, Lady Belle, Bull Run, and other mines of this region, led to the formation of the Cove Mining District.

The Beauregard Company installed a mill of eight wooden stamps, and it is stated that their production was from twelve to fifteen thousand dollars per month. At a depth of 65 feet, the vein was five feet wide, and the ore is said to have milled $70.00 per ton.

It is

The original claims located on the Jeff Davis, Bull Run, Lady Belle, Frank, Urbana, and Beauregard veins were 200 feet wide by 1200 feet. in length. In 1875, the Sumner Gold Mining Company was organized and consolidated the principal claims in the district. A sixteen stamp mill was erected, which was increased later to eighty stamps. This eighty stamp mill operated until 1883. The weight of the stamps was 850 lbs., crushing the ore to about 40 mesh, using straight amalgamation, and no attempt was made to save the concentrates. stated that the production of the mill during this period varied from twenty-five to seventy-five thousand dollars per month. At the time of maximum production, the operations were carried on through the Sumner shaft, located on the Big Blue-Sumner vein. This shaft was of six compartments, and equipped with steam driven hoist and cornish pumps. In 1882, a drain tunnel was started from the river level to cut this Sumner shaft at a depth of 260 feet. In 1883, the shaft house, hoist, pump equipment and shaft timbers were destroyed by fire, and the lower levels of the mine flooded. This company completed the drain tunnel over 2000 feet in length to the Big Blue Mine, which drained the upper workings.

After the fire of 1883, ore extraction was confined to stoping above the 240 foot level. The control of the company then passed to the Kern Development Company, who adopted a leasing system.

Up to the time of the organization of the Sumner Company, no definite records of production were kept at the mines. The Sumner Gold Mining Company showed records of production of 151,000 tons, which yielded $1,250,000 or $8.27 per ton. Records of later production mainly from leases show over 37,000 tons of ore extracted from which $13.43 per ton was saved. Total production of the Cove district is estimated as being from $5,000,000 to $8,000,000.

Estimated production of the various producing mines of the district. is as follows:

Beauregard Mine $600,000; Urbana and Frank $200,000; Big Blue $2,000,000; Blue Gouge $75,000; Bull Run $450,000; Jeff Davis $150,000; Lady Belle $500,000; Nellie Dent $100,000; Sumner and North Extension $600,000.