July 1, IPll. 



THE INDIA RUBBER WORLD 



363 



THE INCOMPATIBILITY OF LIQUID INSULATING 

 MATERIALS. 



A VERY interesting point and one not generally known in 

 ** connection with the use of liquid or plastic insulating 

 materials in the manufacture and installation of electrical appa- 

 ratus, is the necessity of avoiding the use on the same job of 

 different materials which are, so to speak, incompatible with 

 each other, says the expert of the Massachusetts Chemical Co. 



There is a mistaken tendency in the electrical trade to apply 

 successive coats of different kinds of materials on the work in 

 hand-field winding, armature coil, or whatever it may be. Such 

 practice is the cause of much disappointment in the behavior of 

 the insulations, for the reason that many which are of good 

 quality individually are robbed of their real value. This loss 

 of quality by intimate physical association is here termed "in- 

 compatibility,"' and its cause and effect among certain insulating 

 substances are due to radical differences in their chemical and 

 physical properties, and may be illustrated by a few examples 

 from actual practice. 



It is well known that shellac is soluble and carried in solu- 

 tion by liquids of the alcohol family, paraffine by liquids of the 

 naphtha family and still other insulating materials by those of 

 the coal-tar family. But these different substances will not mix 

 with each other, and when solutions of them arc applied as 

 successive coats, as insulation on a winding or other part of a 

 piece of electrical apparatus, the result is a composite but non- 

 homogeneous layer which will give trouble sooner or later. 

 The two parts of the layer will not only have no affinity or ad- 

 hesiveness toward one another, but will mutually repel and 

 injure each other. Thus it is impossible to mi.x shellac and 

 parafine, and it is also impossible to produce a strong enough 

 flux or solvent, to make the compound homogeneous. These 

 two different solids, in suspension or solution in a plastic mass 

 in which they are free to flow will separate in exactly the same 

 way as liquids; and any exposure to heat — as in the ordinary 

 use of the electrical apparatus in which the insulation is em- 

 ployed — will cause chemical disturbances that will eventually 

 break down and destroy insulation. 



A MEMORIAL TO H. A. WICKHAM. 



BUBBEE AND AVIATION. 



The important part that rubber is destined to play in aerial 

 navigation is the more thoroughly realized when we consider 

 the number of manufacturers of established reputation, who 

 have entered the field and are devoting careful attention to 

 this new branch of the business. At the Second National 

 Exhibition of Aerial Craft, held in Boston, there was 

 every evidence of the early advent of a new and important 

 industry, in connection with aviation. In addition to recognized 

 manufacturers of aeroplanes of more than national reputation, 

 there were many manufacturers of engines, propellers, fabric, 

 tires and other accessories, whose presence afforded the best 

 proof of the growing importance of this interest and the sig- 

 niiicance attached to it as a field for commercial exploitation. 

 The fact that aerial navigation is generally accepted as a factor 

 in military operations, lends no little to its importane. 



The lightness, strength to resist landing shocks and resiliency 

 to absorb them that are essential features of the aeroplane 

 tire, are provided for particularly in the Palmer system of tire 

 construction that became so widely popular during the bicycle 

 boom. The B. F. Goodrich Company have adopted this prin- 

 ciple in the construction of their special aeroplane tires, and 

 the Palmer aeroplane tires, as they are known, have become 

 recognized as the proper aeroplane equipment. On the "Hudson 

 Flyer," with which he made his famous trip from Albany to 

 New York, Glenn Curtis used the Palmer tire, and it was con- 

 spicuous on a number of the machines shown at the Boston 

 Exhibition. 



IT IS truly and altogether right tliat the rubber trade should 

 ^ recognize H. A. Wickham's service in securing Para rub- 

 ber seed for the Far East, a service not only to the world, but 

 to the planter and manufacturer as well. The action of the 

 Rubber Growers" Association, in London, therefore, described 

 below, will, without doubt, have cordial support. They sent out 

 a circular suggesting that the occasion of the forthcoming 

 Rubber Exhibition in that city furnishes a fitting opportunity 

 for the offering of "some suitable token of recognition to those 

 through whose instrumentality the original seed of the llevea 

 BrasiUeiisis was brought to the eastern hemisphere." thereby 

 forming the nucleus from which the important rublier planting 

 industry of the East has sprung. 



H. A. \VlCKH.\M, 



It is proposed to present a commemorative piece of plate to 

 the Royal Kew Gardens, the management of which arranged to 

 procure the seeds, and to Mr. Wickham, in lecognition of his 

 energy and resource in carrying out this commission, "a more 

 substantial mark of the gratitude of the rubber planters of the 

 Eastern Hemisphere, for the very important part he played in the 

 founding of this great industry."' 



In "The Rubber Country of the Amazon," the editor of The 

 India Rubber World thus speaks of Wickham's achievement: 

 "It is a good thing to remember that Santarem is the place where 

 Wickham, back in the '70s, was installing a small rubber planta- 

 tion and watching for opportunity. Luckily for the planters in 

 the Far East it came, when the big British steamer Amazonas, 

 without cargo and without cash to buy one, hove in sight. 

 Wickham, practically penniless, chartered it for the Indian gov- 

 ernment, stored baskets of Hevea seeds in its huge hold, won 

 hasty clearance from Para for "rare botanic specimens," and 

 got the seeds to the Kew gardens alive and vital. Every 

 Hevea in the Far East and thousands in other parts of the world 

 are a direct result of that act. The British planters should erect 

 a splendid monument at Santarem in honor of Wickham, but 

 they will never do it — w'ith the consent of the Brazilians." 



RITBBEE IMPORTS IN MARCH. 



The imports of crude India rubber for the month of March, 

 1911, amounted in value to $7,700,000. compared with $18,400,000 

 for the same month in 1910. For the nine months ending March, 

 1911, the imports of crude rubber were valued at $58,900,000, as 

 compared with $83,000,000 for the same period ending 1910. 



