Patent Brick Company
Patent Brick Company brickyard, Marin County, California. Courtesy of the California Historical Society. br>
This brickyard was first known as the Blumenberg's Brickyard, established by Jacob H. Blumenberg on February 8, 1864,
when he leased Jacob DeFries' property on the north bank of Gallinas Creek in Marin County, California. Blumenberg
purchased the property of 100 acres from the DeFries Estate on June 2, 1866, and an additional 15 acres of land adjoining
on the east side from John Lucas on August 29, 1868. The brickyard property fronted on the north side of Gallinas Creek
for over 500 yards, extending eastward to San Pablo Bay. Petaluma Road (now Smith Ranch Road and Silveira Parkway) cuts
through the property along with the S.F. & N.P.R.R., which established a station at Brick Yard (Gallinas). Clay was found
in the low hills west of the plant, but the quarry is now developed over.
By 1870, Blumenberg's Brickyard had 48 workers of mostly Irish and German descent. Thomas Fritts, Henry Hammacke,
and Jerry McGunk were the brickmakers and Casper Balch was the brick burner. The bricks were probably sold locally in
Marin County and shipped to San Francisco. Jacob Herman Blumenberg was a realtor in San Francisco. A native of Prussia,
born about 1818, he arrived in New York and became naturalized on November 4, 1845. He
was in San Francisco as early as 1862. He died on September 24, 1875, leaving a wife and a daughter.
In November 1870, the Patent Brick Company was incorporated in San Francisco, for the purpose of manufacturing brick,
pottery, tile, draining and water pipes, burning and sale of lime, manufacture of cement and plaster, and conducting of
any incidental branch of the pottery business. The capital stock was $300,000 of 300 shares. Their office was located at
513 Montgomery Street in San Francisco. The Trustees were Jacob H. Blumenberg, Edward F. Ohm, O. Schlesinger, Henry Kenitzer,
and James H. Harris. Philip Caduc was elected president.
On November 25, 1870, Blumenberg sold the property to the Patent Brick Company for $5,000. A sales yard was opened at 3rd
and Berry streets in San Francisco. The company eventually owned 351 acres of land, with a small residential camp provided
for the workers.
In 1880, William H. De Valin was the superintendent, with 162 workers composed of mostly Chinese, along with Irish, Portuguese,
Swedish, French, and German laborers. In 1900, 73 were employed with mostly Italians under De Valin as superintendent.
The first Hoffman brick kiln in United States was said to have been built by this company. There were four Hoffman kilns and
each one had a capacity of 25,000 bricks per day. Field kilns burning oil were also used as needed. The equipment included
two Quaker soft mud machines, each with a capacity of 40,000 bricks per day, a stiff-mud machine, with a capacity of 100,000
bricks per day, a drier, three dry-pan grinders, a pug-mill, and cutters. A 200-horsepower electric motor was installed in
September 1904. The stiff-mud machine was added in November 1904. A new drier, made by the American Clay Manufacturing Company,
was installed in 1905, containing 26 tunnels, each with a capacity of 6,000 brick. The drier used waste heat blown in by a
pressure fan and two exhaust fans. Interestingly, the company abandoned the use of their stiff-mud machine in 1907, when the
wires kept breaking due to the hard pebbles in the brick. So, some wire-cut bricks were made here from November 1904 to
The Patent Brick Company made common brick, pressed brick, fancy brick, and Roman brick. They were producing
1.5 million bricks per month in 1915. The bricks were shipped to market throughout the northern Coast Range communities of
California by ships on Las Gallinas Creek or by rail on the Northwestern Pacific Railroad. During the 1870s, this yard provided
7 million bricks for the original San Francisco City Hall and each of these were stamped "CH" denoting City Hall. This is
the only known instance of a mark placed on Patent-made bricks.
After the 1906 earthquake, which provided a boost in demand for brick to rebuild San Francisco, there was a decline in
demand for building brick as concrete was slowly being the preferred choice in building material. The Patent brick plant
operated intermittently during the final years until it closed permanently in 1918. The site has since been razed and
Remnant brick wall on the plant site of the Patent Brick Company.
Patent bricks in a wall at the plant site.
Common brick is pale red to orange red, with a coat of fine sand on the surface giving it a gritty texture. Some of the
underburned brick may be light orange red to overburned brown to black. The fine sand coating consists mostly of subrounded
clear to orange-stained quartz and minor subrounded yellow chert(?), and black magnetite and iron oxides. The form is good,
edges are irregular, but nearly sharp and the corners are dull or broken. Thin irregular lip is present around top edge
in some bricks. The sides undulate and some show large cavities or open cracks. Some have longitudinal or transverse bulges and
indentations, probably from the result of stacking. The longitudinal bulges are quite common and may be a characteristic feature.
The top face is rough, pitted, with longitudinal strike marks. The bottom face is flat and smooth. No brand marks were seen on
any of the bricks at the brickyard site. The interiors of these bricks are known to vary from 10 to 30 percent clasts, ranging
up to 1/2 inch across, set in a vitrified porous to compact red sandy clay body. One type shows about 30 percent clasts of well-rounded,
flattened, vesicular to aphanitic red basalt, some with gray to black interiors, well-rounded red and yellow quartzite,
subrounded to subangular red chert, subangular white quartz, some orange stained while others are clear, white subangular
quartz-feldspar granitic rock, where the feldspar may alter to white or yellow clay, round black iron beads, sometimes found
in clusters or patches, and rare black carbonized wood fragments. Another type shows 10 percent of mostly quartz and granitic
rocks, along with minor amounts of the other clasts listed above. These two types, and gradations between them, indicate a
change of source materials used over time. Further study of the distribution of Patent bricks will hopefully reveal the relative
ages of the different types of materials used. This brick was made using the hand-molded, sand-struck, soft-mud process.
Length 8 - 8 1/2, width 3 1/2 - 4 1/8, height 2 1/2 inches.
Patent brick bottom face.
Patent brick top face.
View of the interior of the Patent brick showing mostly rounded basalt clasts.
View of the interior of the Patent brick showing equal amounts of red basalt and white quartz clasts.
Interior view of the Patent brick showing mostly white quartz and quartz-feldspar clasts.
Patent fancy brick showing a key shaped form from the Patent kiln site. Photo courtesy of Shilzony.
Patent fancy brick showing a hexagonal shaped form from the Patent kiln site. Photo courtesy of Shilzony.
Patent fancy brick showing a single point edge, or exterior octagon form, from the Patent kiln site. Photo courtesy of Shilzony.
Patent fancy brick showing a recess cap form from the Patent kiln site. Photo courtesy of Shilzony.
View of an eroded Patent brick marked "CH" for the San Francisco City Hall, c. 1870s.
Note the rounded pebbles of basalt and white quartz and quartz-feldspar clasts.
No descriptions are available for other types of Patent bricks.
Aubrey, Lewis E., The Structural and Industrial Materials of California,
California Mining Bureau Bulletin 38, 1906.
Copyright © 2009 Dan Mosier
Bradley, W.W., Mines and Mineral Resources of Portions of California, Part 2: The Counties of Colusa,
Glenn, Lake, Marin, Napa, Solano, Sonoma, Yolo, California State Mining Bureau 14th Report of the
State Mineralogist, for the Biennial Period 1913-1914, 1916.
Brick and Clay Record, v. 21, no. 3, 1904, p. 121.
Brick and Clay Record, v. 23, no. 4, 1905, p. 135.
Brick and Clay Record, v. 23, no. 5, 1905, p. 163.
Brick and Clay Record, v. 26, no. 6, 1907, p. 305.
California Historical Society, Patent Brick Company billhead, 1888.
Crawford, J.J., Los Angeles County, California State Mining Bureau
Twelfth Annual Report of the State Mineralogist, 1894.
Daily Alta California, August 1, 1862.
Federal Census Records, 1870.
Federal Census Records, 1880.
Federal Census Records, 1900.
Great Register of San Francisco, 1867.
Marin County Deed Book E, S.C. Reyburn, Estate of Elizabeth DeFriee, to Jacob H. Blumenberg, 16 July 1866, p. 609.
Marin County Deed Book G, John Lucas to J. H. Blumenberg, 26 August 1868, p. 287.
Marin County Deed Book H, J. H. Blumenberg to the Patent Brick Company, 25 November 1870, p. 601.
Marin County Directory, 1884.
Sacramento Daily Union, November 29, 1870.
Sacramento Daily Union, October 11, 1875.
San Francisco City Directories, 1871-1918.
Shilzony, photographs of saved Patent fancy bricks, 2007.