Carnegie Brick and Pottery Company
When steel magnate Andrew Carnegie began donating part of his fortunes to new libraries across
the country, a new brick plant was being erected in Corral Hollow Canyon, about 10 miles
southeast of Tracy, in San Joaquin County, California. Four miles west of the brick works
were the Tesla coal mines, where owners John and James Treadwell had supplied the much
needed fuel to Californians since 1896. Now they were to realize the economic value of
clay abundantly adjacent to the steeply dipping coal beds. This package of coal and clay
was later called the "Tesla Formation" of Eocene Age (50 million years old). The Treadwells
found the fire clay, gray clay, and kaolin to be excellent for making brick, sewer-pipe, and
refractory products. This was fortunate for the Treadwells at a time when coal was losing the
fuel market to oil.
From 1902 to 1905, the Treadwells built 14 round kilns, four chimneys, seven long drying sheds,
a grinding and pug mill, a boiler room, a compressed air plant, loading docks, and a three-story
brick building for the extruding and pressing machinery. By May 1903, the plant and kilns were
put into operation. Because the Tesla coal mines already had a railroad built to Stockton,
transporting the clay to the plant only required a spur line to the loading docks and some
On August 18, 1903, the Carnegie Brick and Pottery Company was incorporated with a capital
stock of $1,000,000, divided into 10,000 shares. The first directors were James H. Swift,
Charles A. Gray, O.K. McMurray, M.B. Maynard, C. Bosse, M.A. Murphy, and W.C. Gregg. Michael
A. Murphy was the general manager. Their headquarters was at the Safe Deposit Building in
San Francisco. The company name honored the great industrialist and philanthropist who was
greatly admired by the Treadwells.
Views of the brick works of the Carnegie Brick and Pottery Company.
The plant consisted of the latest patent pressed brick machines, which had a capacity of
20,000 bricks per day. They used the stiff-mud extruding process, and the clay bars were
cut by the Raymond and Berg brick cutting machines. The brand name "CARNEGIE" was stamped
in capital letters on the face of each brick with or without a frog. The sides of the brick
are smooth with even edges and sharp corners. The faces usually display the curved wire-cut
marks, except for the pressed brick.
The kilns were Nonzone kilns, also known as the California round down-draft kilns, 32-feet
in diameter with a dome roof. Each kiln had a capacity of 110,000 bricks per day. Oil burners
provided the heat. Hot air was drawn from the burning kilns through the drying tunnels by a
large Sturdyvant exhaust fan, seasoning 100,000 bricks in 10 hours. Four of the kilns were
served by a 175-foot chimney and another set was served by a 225-foot chimney. Six of the
kilns were served by a 317-foot chimney. Nearby were the long wooden drying sheds, where
the green clay was cured before firing in the kilns. Inside these drying sheds were
Power was provided by a 400-horsepower Corliss engine, a 150-horsepower gasoline engine, a
90-horsepower engine, and two 40-horsepower engines. Elephant boilers provided the steam.
All types of bricks were manufactured at the Carnegie plant. These included face, pressed,
paving, fire, and enamel brick. Carnegie produced a wide range of colors: white, cream, gray,
buff, salmon, red, and brown. They typically display freckles caused by tiny to large black
spots of iron oxide or specks of black coal. Most were wire-cut, but some were pressed or
The enamel bricks are glazed in white, orange, or brown. The glaze was applied to the sides
or on all faces by dipping and brushing. Enamel bricks were pre-stamped with the brand name
on the flat face or in a shallow frog.
The pavers were made of a mixture of clay and shale, and were subjected to a rattling test
of 2,000 revolutions with a loss of only 6.7 percent, and a crushing test of 8,000 pounds
per square inch. Pavers have the name stamped on a flat face.
High-class pressed and face bricks were popular with the local architects for facing buildings.
They came in various shades of gray, buff, cream, red, and salmon colors. These commonly have the brand
name stamped in a shallow frog.
Firebrick typically display a coarser texture with visible grog of white to gray shale. Firebrick
has the name with or without a model number stamped on a flat face, with no frog.
Locomotive fire blocks, arch bricks, decorative bricks, split pavers, architectural terra cotta,
drain tiles, chimney flues, electrical conduits, sewer-pipes, pottery, and artistic sculptures
were also made by this company.
High class brick sold for four cents and pavers for two cents each. Four to ten carloads of
brick, or as much as 80,000 brick per day, were shipped out by rail over the Western Pacific
railroad. Carnegie brick was wrapped in heavy paper for protection against breakage. This
care is demonstrated in the high-class buildings built of perfect Carnegie brick. Total brick
production from Carnegie is unknown, but the writer estimates that the company produced over
68 million bricks in the eight years of operation.
In 1903, there were 110 employees on the payroll, but there may have been as many as 300
employees in later years. The company town of Carnegie was built to supply and shelter the
workers and their families. Carnegie had a store, bakery, school, saloon, and hotel. Two
large bunkhouses were built for 200 single men. 17 cabins were available for families. Carnegie
was mostly an Italian community.
The plant closed permanently in 1911 following a flood that knocked out the railroad and
destroyed many buildings and bridges in the canyon. The stockholders did not want to invest
more money into repairing and rebuilding property that was by that time under the receivership
of a defunct bank. In 1912, former workers at the Stockton Fire and Enamel Brick Company shipped
Tesla clay and the remaining stock of Carnegie bricks at the abandoned Carnegie yard to their plant in
Stockton, where Carnegie brand-named firebrick continued to be made. On February 6, 1916, the
property was auctioned to the highest bidder and competitor, the Gladding,
McBean and Company, for $35,000. The following year, Gladding, McBean and Company razed the
Carnegie plant and transferred the equipment to their plant at Lincoln, California.
Such was the reputation of Carnegie bricks that for many years afterwards, Carnegie brand
bricks were produced at two other plants. From 1912 to 1920, the Stockton Fire and Enamel Brick
Company of Stockton made Carnegie firebrick. From 1920-1932, the Stockton Fire Brick Company
of Stockton made Carnegie firebrick using clays from Amador and Placer counties.
This Carnegie brick was grogged with calcined fire clay, hand-made in sanded molds, and repressed.
It was the best grade of standard brick being produced for resisting high temperatures under
adverse load and spalling conditions. Carnegie brick from the Stockton plant is not easy to
distinguish from the original white Carnegie firebrick. The sanded surface and lack of curved
wire-cut marks on the face are the only distinguishing features for the Stockton brick.
In 1930, the Stockton Fire Brick Company built another plant in Pittsburg, Contra Costa County,
California, to continue their line of firebricks. In 1943, Gladding, McBean and Company purchased
the Pittsburg plant and continued their own line of Carnegie firebrick until 1958. The lower temperature
firebrick was produced from clays from Amador and Placer counties. Carnegie brick from the
Pittsburg plant is easily distinguished from the original by the yellow color, quartz grog,
the oblong shaped outline of the name plate (typical of Gladding McBean and Company bricks),
and the use of the lower case letter "n" in the brand name.
Original Carnegie brick and terra cotta products can still be seen today in many cities and
towns in California. Some of the finest examples include the Sheraton Palace Hotel, Bank of Italy,
and Folger Coffee Building in San Francisco, the Oakland Hotel and Harrison Hotel
in Oakland, the Daniel Best Building and Masonic Lodge Building in San Leandro, the Natural History
Museum in Los Angeles, the Alexandria Building in Napa, and the Bank of Stockton in Stockton.
Carnegie bricks were even used in some of Andrew Carnegie's libraries, such as those still
standing in Livermore and Lodi, California.
Carnegie face brick is white, gray, buff, cream, or salmon. The faces are flat and smooth, with occasional
transverse grooves and curved wire cut marks. Edges are sharp and straight, corners are sharp. Repressed
face bricks will display the repress marks around the top and bottom faces and have rounded edges and
corners. Black or brown iron spots, round to blotchy, are commonly seen in some face bricks. The larger spots are
centered with a tiny hole. The iron spots appear as freckles that range up to 1 inch across. Some of
the buff, white, and gray face bricks display a few tiny iron spots. Curved wire cut marks are visible on
both faces. For the bricks that have been branded, the name "CARNEGIE" in block capital letters is impressed on a
face or in a rectangular frog. The letters span 5 inches in length and 3/4 inch in height. The rectangular frog
is 6 1/4 inches in length and 2 1/4 inches wide, with beveled sides 1/4 inch deep. This brick was made using the
extruded, stiff-mud process.
Length 8 1/2 - 9, width 4 1/8 - 4 3/8, height 2 3/8 - 2 1/2 inches.
View of Carnegie face brick at the Oakland Hotel, Oakland.
View of Carnegie face bricks at the Sheraton Palace Hotel, San Francisco.
View of Carnegie face bricks at the Belshaw Theater, Antioch.
View of Carnegie face bricks showing name impressed in rectangular frog.
View of Carnegie face brick showing name of a different style recessed on the face. Photo courtesy of Richard Nelson.
Carnegie firebrick is buff, white, or salmon. Sides and ends are smooth. Faces have a granular texture of
of coarse, angular, white to gray shale or white feldspar, up to 1/4 inch across. Brown iron spots
are also present in small amounts. Pits may be abundant on the surface. The name with or without
a model number is impressed into the face in block capital letters. The name spans 5 1/2 inches in
length and 3/4 inch in height. Curved wire cut marks are visible on the face, more so on the back
face. Edges are straight and corners are sharp. This brick was made using the extruded, stiff-mud process.
Length 9, width 4 1/2, height 2 1/2 inches.
View of Carnegie firebrick showing the name impressed into the face.
View of the back face of a Carnegie firebrick.
View of the side of a Carnegie firebrick.
Carnegie enameled brick is white or brown. White enamel may be found on one side or one side and
one end. Brown enamel, or salt-glazed, may be found on all faces and sides or on two faces and two
ends. The brick itself may be white or cream color with tiny spots of iron. Enamel bricks were
pre-stamped with the brand name in block capital letters on either the flat face or in a shallow frog.
The name when impressed on a flat face spans 5 inches in length and 7/8 inch in height. The rectangular
frog is 6 1/4 inches in length, 2 1/4 inches in width, with beveled sides 1/4 inch deep. The name in
the frog spans 5 3/4 inches in length, and 3/4 inch in height. This brick was made using the extruded, stiff-mud process.
Length 8 1/4- 8 1/2, width 4 - 4 1/8, height 2 3/8. inches
View of brown and white Carnegie enameled bricks. White enameled bricks donated by Stuart Guedon.
View of the face of Carnegie enameled bricks. Donated by Stuart Guedon.
Red Pressed Brick
Carnegie red pressed bricks are orange-red, red, to dark red, and mostly uniform in color. The form is excellent with
straight and sharp edges and sharp corners, when new. The surface is smooth and usually absent of marks. Some surfaces
may display minor pits and cracks. When eroded, the surface appears similar to the Richmond red pressed brick with a
granular texture. A few tiny white and black specks may be seen on the surface. Stack indentations may be present on
the sides of some bricks. The top and bottom faces are as smooth as the sides. Marked face contains the name CARNEGIE
recessed in boxy block letters that span 7 inches and stand 3/4 inch in height. A faint rectangular name plate outline 1 3/4 inches
wide extends the whole length of the brick. The interior is composed of 1 percent subangular white quartz and 3 percent
black, blistered iron oxide, both less than 1/8 inch in diameter, in a compact, granular, red clay body. Eroded examples
in the 1905 Folger Coffee Building in San Francisco showed coarser internal material ranging from 1/8 to 3/4 inch in diameter.
This brick was made using the dry pressed process. Length 8 1/2, width 3 7/8, height 2 1/2 inches.
View of the marked face of the Carnegie red pressed brick.
View of the unmarked face of Carnegie red pressed brick.
View of the side of Carnegie red pressed brick, showing the smooth surface on the right and the broken surface on the left.
View of the eroded sides of Carnegie red pressed brick in the wall of the Folger Coffee Building, San Francisco.
View of the interior of Carnegie red pressed brick.
View of the arch shaped ends of Carnegie red pressed brick in the wall of the Folger Coffee Building, San Francisco.
Microscopic view of the interior of Carnegie red
pressed brick (50x, field of view is 1/4 inch).
Red Wire-Cut Brick
Carnegie red wire-cut bricks are orange-red to dark red, and mottled in color. The form is excellent with
straight and sharp edges and sharp corners, when not broken. The surface is smooth and some surfaces may display minor
pits and transverse striations. A few white and black specks may be seen on the surface. Stack indentations may be present
on the sides of some bricks. Flashing color of darker shades of red may be present. The top and bottom faces have angled velour
texture with wire-cut grooves normal to the velour texture. The faces are pitted. Some bricks spall easily. The Marked face
contains the name CARNEGIE recessed in block letters that span 5 1/2 inches and stand 3/4 inch in height. The interior is
composed of 5 to 15 percent subangular cream feldspar and subrounded red chert, as much as 1/2 inch in diameter, and round
black, blistered iron oxide, 1/8 inch in diameter, in a compact, fine orange-red clay body that is heavily streaked with
white clay. This brick was made using the stiff-mud extruded and wire-cut process. The size is larger than standard building brick.
Length 9, width 4 1/4, height 2 1/2 inches.
View of the marked face of the Carnegie red wire-cut brick.
View of the unmarked face of Carnegie red wire-cut brick.
View of the side of Carnegie red wire-cut brick, showing dark red flashing.
View of the interior of Carnegie red wire-cut brick, showing the streaks of white clay.
Microscopic view of the interior of Carnegie red
wire-cut brick (50x, field of view is 1/4 inch).
Red Paving Brick
Carnegie red paving bricks are dark red, and mottled in color. The form is excellent with straight rounded edges and rounded
corners. Repress lines are present on all edges. The surface is rough and bumpy, caused by small nodules of clay protruding the
surface. Some surfaces may display minor pits and cracks. Some are crackled. A few white and black specks may be seen on the surface.
Stack indentations may be present on the sides of some bricks. Flashing color of brown may be present. The top and bottom faces
have angled velour texture with wire-cut grooves normal to the velour texture. The faces are pitted and also contain the bumpy nodules
of clay. Marked face contains the name CARNEGIE recessed in block letters that span 5 1/8 inches and stand 3/4 inch in height. The
interior is composed of 10 percent subangular cream feldspar, round white clay, and round black, blistered iron oxide, all as much as
1/4 inch in diameter, in a compact, vitrified dark red to gray clay body. The brick is dense and heavy. This brick was made using the
stiff-mud extruded and wire-cut process. Length 9 1/8, width 4 1/2, height 2 1/2 inches.
View of the marked face of the Carnegie red paving brick.
View of the unmarked face of the Carnegie red paving brick.
View of the side of the Carnegie red paving brick, showing stack indentations.
View of the end of the Carnegie red paving brick, showing the bumpy clay nodules on the surface.
View of the interior of the Carnegie red paving brick, showing the dark red clay body.
Microscopic view of the interior of the Carnegie red paving brick
with the dark red clay body (50x, field of view is 1/4 inch).
View of the interior of the Carnegie red paving brick, showing the gray clay body.
Microscopic view of the interior of the Carnegie red paving
brick with the gray clay body (50x, field of view is 1/4 inch).
Alameda and San Joaquin Railroad Inspection Report,
unpublished report, 1904.
Copyright © 2006 Dan Mosier
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