A high-quality shale was discovered in 1901 by James Doyle and James R. Miller on the river banks south of Lake Washington. E. J.
Matthews joined them in forming the Renton Clay Company to mine the shale. In 1902, a paving brick plant was erected on 40 acres
at Renton, King County, Washington, producing 25,000 bricks per ten hours. At Taylor, Arthur Denny opened a clay mine and formed the Denny Clay
Company in 1889 to manufacture sewer pipe, firebrick, building brick, and paving brick.
In May 1905, the merger of the Denny Clay Company and the Renton Clay Company resulted in the formation of the Denny-Renton
Clay & Coal Company of Seattle, Washington, with a capital stock of $1,000,000. Officers of the company were
Moritz Thomsen, James R. Miller, E. J. Mathews, Peter Larson, and T. L. Greenough. This company was to build the largest paving
brick plant in the state at Renton. The machinery was also upgraded. Plant employment grew to 500.
Shale and coal of the Renton Series of the Eocene Puget Group were mined originally from underground gangways. The gray shale unit
is 150 feet thick and horizontal. The shale was removed by blasting. A bed of gravel above the shale had to be removed by
hydraulic sluicing. By 1922, shale was stripped mined from the hilltop. Shale layers differed a little in color and texture
and in grain size, but these were mixed together and all used. The composition of the shale was similar to average vitrified
brick shale. The Renton shale is a little higher in silica and a little lower in alumina and iron than the average, while the
total fluxing substances is the same. This shale has good plasticity and high tensile strength, making it excellent for high-grade
paving brick. The coal seam was mined with the shale and used for fuel in the plant.
The shale was delivered by gravity and conveyor belts to two large storage bins. Then it was put into a jaw crusher and reduced
to large lumps. Then it went to four dry pans, where it was thoroughly pulverized and screened, and then put into storage bins
until needed. Five mixtures of clay were used. The clay was then tempered in two large horizontal pug mills.
In 1910, the plant had two Hatfield-Penfield stiff-mud machines with automatic wire-cutters. One had a capacity of 30,000 and
the other 75,000 brick per 10 hours. There was also a dry press brick machine with a capacity of 20,000 brick per 10 hours.
There were also four Eagle Repress Machines for repressing paving brick. The bricks were dried in 23 waste heat tunnel dryers.
Each tunnel was 110 feet long. In 1910, the bricks were fired in nine round downdraft kilns, 34 feet in diameter, and five
square kilns, each with a capacity of 200,000 brick. Total kiln capacity in 1910 was 2 million brick. By 1922, this was
increased to 10 rectangular kilns and 8 round down-draft kilns. Total capacity was 300,000 brick per day. It required 11 days
to burn building bricks and 14 to 15 days to burn pavers, with an additional 8 to 10 days for cooling.
The main building was 145 by 175 feet, four stories high. The machinery was driven by electricity from eight motors, ranging
from 10 to 150 horse power. The plant stood next to the Columbia and Puget Sound Railway.
In 1911, the plant was enlarged to keep up with demand. In 1912, the plant was burning 180,000 brick per day, reported to
be the largest in the world at that time. By 1917, the plant was producing 58 million paving bricks a year.
The Renton plant became famous for its superior vitrified paving brick and block. Standard paving brick measures 8 3/8 by 4
by 2 1/2 inches and weighs 7 pounds. They were laid 60 to the square yard. Paving block measures 8 1/2 by 4 by 3 1/2 inches
and weighs 10 pounds. They were laid 43 to the square yard. The edges of both types of paving bricks were beveled to 1/4 inch.
Hill-climbing blocks were beveled to 1/2 inch on one edge. Buff face brick, red pressed brick, vitrified sewer bricks,
acid bricks and special shapes were also made. About 1922, they introduced their satin builder brick, which was a dark red satin
brick. The paver builder brick was also popular at that time. The paving bricks were marked on the face in recessed block
letters as DENNY RENTON. The Museum of History and Industry in Seattle has an example marked with a hyphen as DENNY-RENTON.
Most of the paving bricks were shipped to Seattle. Some of the earliest paving bricks were used on 1st and 3rd avenues,
and Common and Pike streets in Seattle. In 1911, the city of
Renton accepted the company's offer for its second-class brick as a paving base free of charge for $75,000
worth of paving work. In 1912 vitrified building pavers were sent to Pendleton High School. Missoula, Missouri, ordered
1,250,000 paving brick. In June 1913, the San Francisco Board of Public Works ordered 100,000 paving blocks at $47.50 per
thousand. These bricks were laid on First Street in San Francisco. Test bricks were laid earlier on Powell Street free of
charge and this encouraged San Francisco to order the same for First Street. In 1913, paving bricks were used on 6,000 feet
of roads near Ellensburg, Kittias County. In 1921, Seattle ordered 600,000 paving brick. Paving bricks were also shipped to
points as far as Tokyo, Japan, and India.
From 1905 to 1913, B. F. Cake was the plant superintendent. In 1922, Mr. Geijsbeck was the manager and James Adderson was plant
superintendent. At the company office in Seattle, the manager was Frank C. Moore and G. L. Rogers, a ceramic engineer, was in
charge of firebrick sales. The Denny-Renton Clay & Coal Company owned three plants in Washington and one in Oregon, with
each plant specializing in different clay products. It was the largest and dominant clay products company in the Pacific Northwest.
During the 1920s, demand for paving brick declined when automobile traffic increased and asphalt became the preferred road paving
material. Demand for other clay products also declined when concrete replaced brick and terra cotta wall tile in structural
building materials. In 1927, Gladding, McBean & Company, a California-based company, purchased the Denny-Renton Clay &
Coal Company and turned the Renton plant into a firebrick maker. See Gladding, McBean & Company, Renton, for the continuation
of the history of the Renton plant.
The Denny Renton paving block is red to dark red and uniform in color. Form is good with straight edges and smooth surfaces.
The edges and corners are rounded. Surface displays white quartz averaging 1/16 inch in diameter. Repressed lines
are present along the longer edges. Stack indentations on the sides
may deform the brick. Conveyor imprints of short transverse parallel dashes may be seen on the side. The faces display
steep curved wire-cut grooves on a velour texture. The marked face displays the company name of "DENNY RENTON" in recessed
block letters that span 4 3/8 inches and stands 1/2 inch. The mark is centered inside a shallow rectangular frog that
is 4 7/8 inches long and 1/2 inch wide. About 3/8 inch from the ends of the frog are round slightly raised screw imprints
7/8 inch in diameter. Near each corner of the face is a raised round lug 3/4 inch in diameter. The unmarked face may
display conveyor imprints of longitudinal parallel dashes. Interior clay body is fine grained vitrified clay with 2 percent
milky white subangular to subrounded quartz and subrounded black basalt, both less than 1/8 inch in diameter. This block
is tough, massive, compact, and heavy, weighing 10 pounds. It was made using the stiff-mud process and repressed.
Length 8 5/8, width 3 3/4, height 3 1/2 inches.
American Clay Magazine, v. 8, no. 1, July 1913.
Architect and Engineer, v. 16, no. 3, April 1909, p. 146.
Bambergers are in Clay Works Merger, Clay Record, v. 26, no. 511, 15 June 1905, p. 35.
Clay Record, v. 26, no. 12, 30 June 1905, p. 37.
Clay Worker, v. 56, no. 2, August 1911, p. 175.
Clay Worker, v. 59, no. 6, June 1913, p. 886.
Clay Worker, v. 60, no. 2, August 1913, p. 167.
Clay Worker, v. 75, no. 4, 25 March 1921, p. 394.
Clay Worker, v. 78, no. 5, November 1922, p. 438.
Coast Craftsmen, American Clay Magazine, v. 10, no. 3, January 1915, p. 12.
Elam, Anna, Museum of History and Industry, Seattle, written communications, 2019.
Evans, George W., The Coal Fields of King County, Washington Geological Survey Bulletin 3, 1912.
Glover, Sheldon L., Clays and Shale of Washington, Washington Division of Geology Bulletin 24, 1941.
Hilding, Tina, Renton history built with bricks, Black Diamond History, accessed 3 November 2017,
https://blackdiamondhistory.wordpress.com/2017/08/26/renton-history-built-with-bricks/.
Matsumura, JoAnn, written communications, 2017.
Pacific Coast Architect, v. 2, no. 5, February 1912, p. 235.
Pacific Coast Architect, v. 3, no. 3, June 1912, p. 432, 443.
Pacific Coast Architect, v. 5, no. 3, June 1913, p. 137.
Roberts, Milnor, Ores, Coals and Useful Rocks of Washington With Manufactured Mineral Products of the State, The College of
Mines Series, Seattle, April 1917.
Shedd, Solon, The Clays of the State of Washington, State College of Washington, Pullman, Washington,
June 1910.
Warren James, Paving the way: King County bricks built roads around the world, Seattle Post-Intelligencer, accessed 4 November 2017,
https//blackdiamondhistory.wordpress.com/2014/12/07/paving-the-way-king-county-bricks-built-roads-around-the-world/.
Contact Dan Mosier at danmosier@earthlink.net.