November 1, 1911.] 



THE INDIA RUBBER WORLD 



69 



evidence that rubber tree culture may be possible. That these 

 figures must be fairly accurate, and that they must have held 

 good for many years is furthermore proven by the photographs. 

 The figures show the maximum, minimum, and average monthly 

 temperatures in degrees, Fahrenheit, and the rainfall in inches 

 for this particular year at San Diego and Santa Barbara. 



Temperatures. 



San Diego. 



Max. Mill. Av. 



January 73 35 S3 



February 84 41 60 



March 82 40 56 



April 75 43 59 



May 73 51 61 



June 80 52 63 



July 81 59 68 



August 75 60 67 



September ... 79 50 65 



October 78 54 65 



November ... 86 45 61 



December .... 79 43 58 



Rainfall. 



San Santa 



Diego. Barbara 



January 3.27 12.46 



February 45 2.34 



March 1.62 5.64 



April 13 .27 



May 07 T 



June 19 .16 



July 03 .00 



August 00 ;03 



September . .. .00 T 



October 1.71 6.23 



November ... .00 T 



December ... .43 1.80 



amount of rubber could be expected from trees planted hereafter. 

 Such tapping would prove too whether or not the rubber from 

 these Fictis trees compares in quality with the rubber secured 

 from like wild trees or trees cultivated in some other country. 

 While everything seems to point to a possible profitable new 

 field, it would seem advisable to move slowly. There are suf- 



7.90 28.93 Total for year. 



Pl.vte No. 2. — Ficus Elasiica in P.\rk i.\ b,\N Diego, l.\l. 

 [Tree measures 64 feet across.] 



It will be noticed that the minimum temperature for the year, 

 namely 35 degrees, was reached at San Diego in January, in 

 which month the photographs were taken. 



Plate No. 1 represents a vigorous specimen which stands in 

 the grounds of the Hotel Coronado, Coronado Beach at San 

 Diego. The photograph plainly shows that the lu.xuriant foliage 

 was not affected by the low temperature. 



Plate No. 2 shows an exceptionally large tree located in a 

 public park in San Diego. From the trunk of this tree to the 

 tip of its branches it measures thirty-two feet. 



All the specimens herewith illustrated show a thoroughly 

 healthy development uninterrupted for many years, and also 

 indicate that the relatively sandy soil must be quite favorable. 



The fact that a rubber tree has been successfully grown in 

 a certain locality is, however, no proof that that same tree will, 

 at the proper age, give a normal yield of rubber. Neither does 

 it necessarily follow that such a tree must produce less rubber 

 than it would in its native habitat, for have not the fruit trees 

 of California, in almost all instances, brought forth better and 

 more fruit than the corresponding trees in our eastern states? 

 It may be argued that this comparison does not hold good be- 

 cause rubber trees do not grow in the east. True, but rubber 

 trees grow in some pretty hard climates and in some pretty 

 poor soils — under considerably worse conditions than are found 

 in California. Careful experimenting alone will solve the com- 

 mercial side of the question. The trees now existing could be 

 systematically tapped to ascertain sufficient data as to what 



ficient favorable data to warrant experimental plantings at such 

 governmental experimental stations as are located in that section 

 of our country. Such plantings should not be confined to the 

 one tree now known to thrive there, but should include every 

 known species and a sufficient number of specimens of each 

 species in order to arrive at some definite and reliable informa- 

 tion. F. H. HUNICKE. 



KUBBER AT THE ARNOLD ARBORETITM. 



For many years it has been the ambition of scientists, rubber 

 manufacturers and others to find some rubber producer that 

 can be successfully grown in the United States, or more broadly 

 in the temperate zone. Experiments have been made with the 

 milk weed, the Aesclepias Cornuti, in Canada, the United States 

 and Germany, with the Ekanda tuber, with the Manihot Glaziovii 

 in the United States and Germany and with many other trees, 

 shrubs, vines and herbs. So far none have been found com- 

 mercially profitable, but that does not prove that they never 

 will be. 



Some time ago the newspapers far and wide announced that 

 the great out-of-doors forestry museum of Harvard University, 

 Arnold Arboretum, was in possession of certain Chinese rubber 

 trees adapted to the rigorous climate of New England and that 

 they were growing finely. Professor C. S. Sargent in 1907-9 

 sent, for the arboretum, an expedition to China under the leader- 

 ship of E. T. Wilson, a well known explorer and botanist. 

 Among the hundreds of specimens that he brought back was 



