Chapter XXIII: The Properties of Rubber

Raw rubber--Physical tests--Vulcanised rubber--"Inner
qualities" of raw rubber--Defects of crepe and sheet--
Variation in physical properties--Rate of cure--Influence of
various factors in raw rubber on rate of cure--Other types of
plantation rubber--Fine para 313

INDEX 327

LIST OF ILLUSTRATIONS

PAGE
SEEDS, SHOWING VARIABLE SIZE, SHAPE, AND MARKING 2
FELLING LIGHT (SECONDARY) JUNGLE 3
SEEDLING, SHOWING ROOT-SYSTEM WITH SEED STILL ATTACHED 4
NEW CLEARING 5
TYPICAL YOUNG CLEARING, AGED ABOUT THREE YEARS, PLANTED ON
VIRGIN SOIL. ORIGINAL JUNGLE TIMBER SLOWLY ROTTING 6
LIGHT JUNGLE 7
DENSE JUNGLE 8
CLEARING READY FOR PLANTING 9
NEW CLEARING: SLOPES "HOLED" FOR PLANTING; FLAT AREA BEING
DRAINED 11
TYPICAL YOUNG CLEARING, WITH TIMBER 15
TYPICAL YOUNG CLEARING, WITH TIMBER 17
TYPICAL YOUNG PLANTED AREA 20
ANOTHER EXAMPLE OF A RECENTLY PLANTED AREA 21
WIDELY PLANTED YOUNG AREA, JUST READY TO BE BROUGHT INTO
TAPPING 24
FIELD OF OLD RUBBER TREES IN WHICH THINNING HAD BEEN DELAYED
TOO LONG 25
TWO CUTS ON A QUARTER CIRCUMFERENCE, ON AN OLD TREE 31
THE SINGLE CUT ON A QUARTER CIRCUMFERENCE, ON AN OLD TREE AND
ON RENEWED BARK 33
SINGLE CUT ON HALF CIRCUMFERENCE (HALF-SPIRAL) 35
A [V]-CUT ON HALF THE CIRCUMFERENCE 37
SINGLE CUT ON TWO-FIFTHS OF CIRCUMFERENCE 41
EFFECTS UPON RENEWED BARK OF PREVIOUS TAPPING 44
ANOTHER EXAMPLE SHOWING THE EFFECTS OF PREVIOUS TAPPING 45
1. SHOWING EFFECT OF "WINTERING" 48
2. NEW GROWTH OF YOUNG LEAF ON SAME TREE 49
EFFECTS OF DISEASE--"MOULDY ROT" 50
EFFECTS OF DISEASE--"MOULDY ROT" 51
EFFECTS OF DISEASE--"MOULDY ROT" 52
EFFECTS OF DISEASE--"MOULDY ROT" 53
RAISED VERANDAH FOR RECEPTION OF LATEX; LIKEWISE EQUIPPED WITH
FACILITIES FOR CALCULATING INDIVIDUAL DAILY "YIELD PER
COOLIE" BY SAMPLING OF LATEX 66
END-SECTION SKETCH OF VERANDAH, ETC., SHOWING A GOOD METHOD
FOR RECEIVING LATEX AND FILLING TANK 70
RAISED VERANDAH FOR RECEPTION AND HANDLING OF LATEX 71
ANOTHER SET OF DILUTION TANKS ON RAISED VERANDAH 72
TWO VIEWS OF DILUTION AND MIXING TANKS 81
UNIT MODERN COAGULATING TANK (TWO VIEWS) 91
ANOTHER BATTERY OF TANKS, WITH DILUTION TANKS, RAISED, ON THE
RIGHT 92
CLOSER VIEW OF FOREGOING 93
ANOTHER BATTERY OF TANKS, WITHOUT DILUTION TANKS OR MEANS OF
GRAVITATING LATEX 95
A SHEETING TANK CONTAINING COAGULUM FOR CREPE PREPARATION 96
A "BATTERY" OF SHEETING TANKS (PATALING ESTATE). DILUTION
TANKS, RAISED, ON THE LEFT 97
THE OLD METHOD OF "DRIPPING" FRESHLY ROLLED SHEETS WITHIN THE
FACTORY 108
THE NEWER METHOD OF HANGING IN THE OPEN AIR 109
THREE GRADES OF CREPE RUBBER 111
A WASHING SHED 112
DRYING GRAPH. PALE CREPE (THIN) 140
A SHIPMENT OF RUBBER, PACKED AND READY FOR TRANSPORT 155
ON ITS ROAD TO THE RAILWAY: BULLOCK-CART TRANSPORT 157
A BATTERY OF MACHINES 165
"THIRD MILE" TYPE; HORIZONTAL DRUM 190
"THIRD MILE" TYPE OF FURNACE, USED IN CONJUNCTION WITH "THIRD
MILE" SMOKE-HOUSE 190
SIDE SECTIONAL ELEVATION (PATALING TYPE OF FURNACE) 193
PATALING TYPE OF FURNACE 193
LARGE SMOKE-HOUSE OF ORDINARY CONSTRUCTION, WITH SHIELDED
VENTILATORS PERMANENTLY OPEN 194
BRICK AND CEMENT SUPERSTRUCTURE OF FURNACE INSIDE THE
BUILDING, BUT FED FROM OUTSIDE 195
GENERAL VIEW OF SHELTERS COVERING APPROACHES TO FURNACES 196
NEAR VIEW OF SHELTER 197
"THIRD MILE" TYPE OF SMOKE-HOUSE 199
GENERAL VIEW OF DOUBLE "DEVON" TYPE OF SMOKE-HOUSE 201
GENERAL VIEW OF DOUBLE "DEVON" SMOKE-HOUSE AND FACTORY
BUILDINGS 202
VIEW OF PLATFORM OF "DEVON" SMOKE-HOUSE; DOORS OF COMPARTMENTS
OPEN, AND ONE RACK PARTIALLY WITHDRAWN 203
DOUBLE "DEVON" SMOKE-HOUSE OF BRICK, WITH ROOF OF CHINESE
TILES, SHOWING LOADING PLATFORMS WITH RACKS WITHDRAWN FROM
SMOKING CHAMBERS 204
SIDE-VIEW OF PRECEDING PHOTOGRAPH, SHOWING EXTERNAL
ARRANGEMENT FOR STOKING FURNACES 205
FRONT VIEW OF DOUBLE "DEVON" TYPE OF SMOKE-HOUSE 206
SIDE-VIEW OF DOUBLE "DEVON" TYPE OF SMOKE-HOUSE 207
THE NEW "BARKER" TYPE OF SMOKE-HOUSE: A SMALL UNIT 210
SUGGESTED ARRANGEMENT OF BUILDING 218
THREE SPECIMENS OF FINE PALE CREPE SUFFERING FROM "SPOT"
DISEASE 237

THE PREPARATION OF PLANTATION RUBBER