ECV1850 Plaque:
Hendy Stamp Mill

[ Photo of Stamp Mill. ]

[ Photo of Stamp Mill. ]

[ Photo of plaque #1. ]

(First plaque, to the left of the stamp mill.)

During the California Gold Rush, Hendy Iron Works
built mining and stamp mill machinery exclusively.
They supplied mining operations around the world
with stamp mills that could operate as a single
unit or as multiple units of up to 100 stamps,
with 20-40 stamps as the most common installation.

Following the 1906 earthquake, John Hendy moved
the iron works from San Francisco to Sunnyvale,
lured here by the offer of free land, and was
operational in 1907. Hendy Iron Works was the
first heavy industry in Sunnyvale and was
Santa Clara Valley's largest manufacturing
concern at that time.

This Hendy "California" stamp mill represented
the finest machine technology available in the
early nineteen hundreds. This type of gravity
stamp mill was one of the most important factors
in the extraction of gold, silver and copper ores,
from hard rock mines.

The stamp battery was activated by rotating the
pulley wheel, made of air dried California
yellow pine, which turned the camshaft and cams,
made of 'adamantine' chrome steel, at 50
to 55 RPMs. The cams raised the 1,000 lb. stamps
to a pre-set height, then the stamps would fall,
pulverizing the gold ore between the stamp heads
and the mortar dies. The pulverized ore was
sifted by a special screen placed across the
front of the mortar so the precious metal could
be retrieved. It could take as much as 50 tons of
ore-bearing rock to recover as little as
2 1/2 ounces of gold.

The reputation and superiority of "Hendy" mortars
is based on experience, design and quality.
To the interested engineer, investor or miner
this results in the best graviy stamp battery
units of five stamps and over.

Source: Hendy Iron Works catalog - July, 1911.

Descriptive plaque donated by
Mountain Charlie Chapter No. 1850
E Clampus Vitus

May 11, 1996 - And so recorded!

 Victorian Bar

[ Photo of plaque #2. ]

(Second plaque, to the right of the stamp mill.)

This 5-stamp mill was bult by Joshua Hendy Iron Works
in Sunnyvale around the year 1918. Fredrick W. Peterson
purchased the mill in 1919 and began stamping out a family
fortune at his gold mine in Pine Grove, California.

In 1986 the mill was purchased by the Iron Man Museum
of Sunnyvale from Frederick's Great Grandson, Eric.

The restoration and installation of this mill was completed
in April of 1996 through the efforts of the Iron Man Museum,
the Sunnyvale Historical Society and Museum Association,
Mountain Charlie Chapter 1850
E Clampus Vitus,
and many members of our community.

Dedicated May 11, 1996

As a gift to the City of Sunnyvale and its citizens.

Mountain Charlie Chapter No. 1850
E Clampus Vitus
"Right Wrongs Nobody"

 Victorian Bar

Both plaques are located at the
Martin Murphy Jr. Historical Park.
On the South-East corner of
Sunnyvale Avenue and California Avenue.
Santa Clara County, CA.

  Hendy Stamp Mill  
WGS84 Datum
N 37.38147°
W 122.02699°

 Hendy Iron Works ID Plate

Hendy name plate at base of cast-iron streetlight pole,
San Jose Historical Museum.

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