Vitrified Products Company
In 1922, following the discovery of a clay deposit at Linda Vista in San Diego County, the Vitrified Products
Company was organized to mine clay and manufacture vitrified clay products. Victor Kremer was president, Siegfield
Hagen, vice-president, and George W. Kummer was the general manager and secretary. Other board members were
Rufus Choate and John F. Forward, Jr.
Victor Kremer owned the clay deposit, which was on 175 acres of land on a ridge at the head of a small
tributary of Escondido Creek and was part of the Eocene La Jolla formation. The clay deposit consists of a lower 20 feet
of sandy, white to buff mottled claystone overlain by 18 feet of lavender and buff mottled claystone. The clay
layers dipped 10 degrees to the northwest.
The clay was mined by two open pits on the west side of the ridge. The southern pit was the largest being about
200 feet long, 100 feet wide, and over 30 feet deep. The northern pit was 120 feet long, 80 feet wide, and over
20 feet deep. An electric shovel with a daily capacity of 300 tons dug the pits. It is estimated that several
thousand tons of clay was removed by the company. A spur line connection was made with the Santa Fe Railroad for
In Old Town San Diego, at the present intersection of Jefferson Street and the Pacific Highway, the company
erected their brick plant on 23 acres of land at an initial cost of $175,000 in 1923. The plant consisted of 12 kilns
with a capacity of 150,000 brick per day, a two-story building, a grinding and screening room, a machine
room, and a dryer. The equipment included a dry press, hollow building tile, sewer pipe, and conduit tile machinery,
and over 100 dryer cars. There were two separate railroad sidings, one for raw material and one for finished
In 1924, the company built their office, a $4,000 tile office building, at 2925 Jefferson Street. From 1923 to 1942,
the company produced a variety of products, including building brick, face brick, paving brick, sewer brick,
drain tile, hollow tile, roofing tile, and electric conduit tile. Hollow tile, roofing tile, sewer pipe, and
conduit tile production began in 1924.
V.P.C. Face Brick
Mottled buff to salmon brown on smooth surface, some burnt to black. Sides may show brownish flashing in transverse or longitudinal directions.
Form is excellent with sharp straight edges and sharp corners, when not broken. Short edges may be rounded or sharp. The faces show strong curved grooves
and a slight velour texture from wire-cuts. Large pits are common on the faces. Sides are smooth with a few transverse grooves. Marked face displays
in large squarish block letters the company abbreviations V.P.C. recessed, centered, and spanning 6 1/2 inches and standing 1 3/4 inches in height.
Periods are square shaped. Interior is granular and contains as much as 25 percent of mostly subangular gray to orange stained quartz, white granite,
lesser rounded red clay, brown iron oxide, all up to 1/4 inch in diameter, in a buff or pinkish clay body. This brick was made using the stiff-mud process, extruded and wire-cut
on the faces. The size is notably large for building brick. Length 9, width 4 1/2, height 2 1/2 inches.
View of marked face of a V.P.C. face brick. Donated by George L. Kennedy.
View of unmarked face of a V.P.C. face brick. Donated by George L. Kennedy.
View of side of a V.P.C. face brick. Donated by George L. Kennedy.
View of side of a V.P.C. face brick showing brown flashing. Donated by George L. Kennedy.
View of the interior of a V.P.C. face brick.
Microscopic view of the interior of a V.P.C. face brick (50x, field of view is 1/4 inch wide).
View of bats of V.P.C. face brick. Photo courtesy of Martyn Tagg.
Brick and Clay Record, v. 60, no. 10, 1922, p. 790.
Copyright © 2010 Dan Mosier
Brick and Clay Record, v. 62, no. 10, 1923, p. 880.
Brick and Clay Record, v. 63, no. 3, 1923, p. 198.
Brick and Clay Record, v. 64, no. 12, 1924, p. 896.
Brick and Clay Record, v. 65, no. 4, 1924.
Brick and Clay Record, v. 65, no. 9, 1924, p. 626.
Kennedy, George L., personal communications, 2014.
Symons, Henry H. California Mineral Production and Directory of Producers For 1943.
California State Mining Bureau Bulletin 128, 1944, 222 p.
Tagg, Martyn D., written communications, 2010.
Weber, F.H. Jr. Geology and Mineral Resources of San Diego County, California.
California Division of Mines and Geology County Report 3, 1963.