Guayule Rubber Industry in Salinas, California, ca. 1942
Guayule Rubber Industry in Salinas, California, ca. 1942
BANC PIC 1962.006--fALBThe Bancroft Library
University of California
Berkeley, California 1997
- Processed and encoded by:
- California Heritage Digital Image Access Project staff in The Bancroft Library and The Library's Electronic Text Unit
- Digital images processed by:
- The Library Photographic Service
- Finding aid completed:
- November 1996
Digital Representations Available
:1 Preparing the seed beds in the nursery. The ground must be finely pulverized. Note the duckboards and the overhead watering system.
:2 New Seed sower. Plants seed in two inch strips with five inch space between. Seed hopper in front, and hopper in the rear.
:3 One of the first seed planters, which broadcast the seed on the ground and covered it with sand.
:4 [Machine working the field]
:5 Nursery seedlings, eight months old, ready for digging and transplanting to the fields.
:6 Topping seedlings prior to digging for transplanting to the fields. Group of General Tire Company officials and wives watching process.
:7 Closeup view of seedling topper.
:8 Another original machine, which Bud Spencer is driving, loosens the dirt around the nursery plants when they have been topped. The roots go straight down for eight to twelve inches and this operation makes it simple for the laborers to gather them, one of the few hand processes in the growth of guayule. Dr. David H. Spence, Stanford University rubber chemist, maintains that the cheapest way to grow guayule is to harvest the plants when they are at this stage. William O'Neil, General Tire's president, believes this system should be adopted for emergency development of a rubber supply.
:9 Laborers picking seedlings from the beds after digging same.
:10 One year old seedling, showing hundreds of flowers. Each flower produces five seeds. Estimated production for a mature plant is between two and five thousand seeds per year. Present seed collecting device, to date, has only collected about ten seeds per plant. Therefore, this device needs perfecting.
:11 Six row seed planter. Each man plants about 50 plants per minute planting them in rows thirty-six inches apart and twenty-eight inches apart in the rows. An electric device on a corn planter check wire makes it possible to cross-cultivate both ways.
:12 Seed planter starting operations on March 5, 1942, the day the President signed the Guayule Rubber Bill. Executives of the General Tire Company acting as the laborers.
:13 Planting operations starting March 5, 1942 by the Forest Service. Have planted 70 acres to date, March 16, 1943.
:14 Cross-cultivation is a simple process with this machine.
:15 Mature seven year old field. This field went 2,850 pounds of rubber per acre in 1941.
:16 From this plant which Juan holds can be extracted a quantity of real rubber equal to 23 per cent of the weight of the plant. The rubber comes from the roots and branches, only the leaves having no rubber content. This plant is seven years old. At this age it reaches its peak in rubber content.
:17 Plow which plows two rows, including the roots, piling them all into one row.
:18 Harvesting device which picks up the two plowed rows of guayule rubber, choppes [sic] it up in a sileage cutting device, and elevates it into wagons to be hauled to the mill.
:19 Harvesting device which picks up the two plowed rows of guayule rubber, chops it up in a sileage cutting device, and elevates it into wagons to be hauled to the mill.
:20 Four year old plant. Note yard stick.
:21 One year old plants.
:22 Seed picking device. Knocks the seed off and collects it in receptacle in the rear by vacuum. (Seed is collected from two rows).
:23 Another seed collecting device that was first developed collected the seed from one row. Apparently these machines are rather inefficient as they have only been able to collect ten seeds per plant, while it is estimated each plant can produce from two to five thousand seeds per year.
:24 After the seed is dried, it is placed in air tight drums where it keeps almost indefinitely.
:25 Mill at Salinas, California which cost $265,000.
:26 Chopped shrub at the bin where it has been dumped from the wagons from the fields. Shrubs go through three sets of rollers before going into the mill proper.
:28 Another picture of the mill.
:29 The first settling tank. The wood silt becomes water logged and goes to the bottom. The rubber floats, together with some cork, the latter being removed by forcing water into the air cells of the cork under 350 pounds pressure, which sinks in the settling tank. This picture is out of order, and should be in following the next two.
:30 Long tubular ball mills are used, using flint stones the size of the fist which come from Norway or Belgium, because of their hardness.
:31 These giant crushers are filled with rocks. Chopped guayule is put in these tanks and rotated so that the rocks crush the wood pulp, and separate it from the rubber.
:32 These stones, imported from Norway, are used as a primary part of the milling process. Search is now being made in America for stones having similar qualities of hardness.
:33 The pulp from the crushers is then transferred to these water filled vats. The wood pulp sinks to the bottom and the rubber and cork rises to the top and is skimmed off.
:34 Rubber being scraped from the trays after drying.
:35 [Man and machinery]
:36 Wet rubber being placed in the trays prior to drying.
:37 Sheet of dried rubber before it is pressed in a box.
:38 Rubber press which presses the rubber into blocks of 100 pounds each - two blocks to a box. This rubber contains about 18 or 20 percent resin and other impurities. One of the problems is the elimination of this resin and particularly, the elimination of the impurities. Dr. D. Spence is working on a plan of purification of guayule rubber.
:39 Dr. D. Spence, well known rubber chemist and specialist, Major Evan W. Kelley of the United States Forest Service in charge of the Government project and Senator Sheridan Downey.
:40 Major Kelley, Senator Downey and Dr. D. Spence. Dr. Spence advocates the planting of the seed thick in the spring and harvesting in the fall, and states that his experiments show that he could get 1170 pounds of pure rubber per acre, which he maintains can be produced at a great deal less cost, and a great deal quicker, than under the transplanting plan.
:41 The Truman Committee in Salinas investigation [sic] guayule rubber, being beseiged [sic] by the mothers of 186 Salinas boys with General McArthur, requesting that something be done to help their boys. Left to right, Senator Kilgore, West Virginia, Senator Ball, Minnesota and Senator Downey, California.
:42 Senator Kilgore, West Virginia, Senator Ball, Minnesota and Senator Walldren, Washington at the guayule rubber mill at Salinas, California where they carried on an extensive investigation and hearing of guayule rubber on March 15, 1942.
:43 Almost a thousand miles of duckboards and wooden rails on which to run the machinery at the new nurseries being built at Salinas. Contract for this job was $283,000.
:44 The site of the 1,000 head labor camp. Contract, $183,000.