California brick

McKnight Fire Brick Company


John H. McKnight, former owner of the McKnight clay pit in Riverside County, once supplied fire clay to several large brick companies in Riverside and Los Angeles counties. In 1919, McKnight went to Tulare County and found a suitable site for a new refractory brick plant at Porterville. He was interested in manufacturing magnesite, chromite, and silica refractory bricks, all materials being available near Porterville.

The McKnight Fire Brick Company was organized in 1919 to build a plant to manufacture high-grade fire brick for use in cupolas, open hearth furnaces, and smelter furnaces. The officers in 1920 were R.S. Elliott, president; E.K. McBride, vice-president; John McKnight, general manager; E.M. Vogel, secretary; and C.M. McKnight, treasurer. The plant was completed in six weeks. No description of this plant was found. The fire brick was stamped with McKNIGHT on the face of the brick. An example of a silica brick, shown below, was found by Blacky Blackwell.

In 1920, due to increasing demand in the San Joaquin Valley for building brick, the company was considering entering that market as well. Plans were made to purchase additional machinery for the manufacture of face brick, building tile, sewer pipe, roofing tile, etc. However, the company decided to merge with an existing building brick manufacturer in Fresno known as the Craycroft Brick Company. The merger occurred in 1921 and John McKnight became vice-president in the firm, which was also known as the Craycroft-McKnight Brick Company.

The plant at Porterville was closed and all of the machinery was transferred to the Craycroft brickyard located on Belmont Avenue in west Fresno. This allowed Craycroft to make McKnight fire brick, but they had replaced the McKnight name with their own on the fire brick.

John Henry McKnight was born in Indiana in 1858. He married Agnes Woodburn in 1882 and they raised five children. They came to California in the 1890s and settled on a farm in Temescal Canyon, Riverside County. In 1901, McKnight discovered a flint clay deposit at Corona, which he developed into a successful clay mine. After opening a refractory brick plant in Porterville, he returned to Los Angeles to continue working in the clay industry. He died on September 23, 1946, at the age of 86 years.

McKnight Brick

The silica brick is gray and has a smooth surface. Worn or eroded surfaces feel gritty. Small grains of white quartz are visible on the surface along with tiny pits. The edges are straight but dull. The corners are dull. On the face is impressed the name McKNIGHT in large block letters, which span 8 1/2 inches and 1 1/8 inches in height, except for the lower case "c", which is 3/4 inch in height. The interior consists of 90 percent white to translucent subangular quartz, less than 1/8 inch in diameter, which are welded together. This brick appears to be made with a brick press. It is an arch-shaped brick. Length 9, width 4 1/2, height 2 1/8 - 1 1/2 inches.

Marked face of the McKnight silica brick

View of the marked face of the McKnight silica brick. Collection of Blacky Blackwell.

Interior of the McKnight silica brick

View of the quartz-rich interior of the McKnight silica brick.

Microscopic view of the interior of the McKnight silica brick

Microscopic view of the interior of the McKnight silica brick showing
welded white quartz and brown iron oxide. (50x, field of view 1/4 inch).

The McKnight magnesite and chromite bricks are not available for description.


Blackwell, Blacky, personal communications, 2013.

Boalich, E.S., Castello, W.O., Huguenin, Emile, Logan, C.A., and Tucker, W.B., The Clay Industry In California, California State Mining Bureau Preliminary Report 7, 1920, p. 101.

Brick and Clay Record, 1901, v. 15, no. 4, p. 171.

Brick and Clay Record, 1902, v. 16, no. 6, p. 280.

Brick and Clay Record, 1919, v. 54, no. 3, p. 244.

Brick and Clay Record, 1919, v. 54, no. 5, p. 425.

Brick and Clay Record, 1919, v. 54, no. 11, p. 999.

California Department of Health Services, California Death Records, Rootsweb, (accessed March 1, 2014).

Federal Census Records, 1900.

Federal Census Records, 1910.

Federal Census Records, 1930.

Funds Ready to Enlarge Porterville Plant, Brick and Clay Record, 1920, v. 57, no. 5, p. 502.

Manufacture of Brick to Be Pushed, Brick and Clay Record, 1920, v. 57, no. 8, p. 677.

Merger of Two California Companies, Brick and Clay Record, 1921, v. 58, no. 4, p. 318.

Plan Expansion to Include Clay Products Manufacture, Brick and Clay Record, 1920, v. 55, no. 5, p. 446.

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