May 1, 1917.] 



THE INDIA RUBBER WORLD 



473 



THE DECLINE OF RUBBER IN PHOTOGRAPHY. 



JUST as the march of progress is ever creating new uses for 

 india rubber, so it occasionally eliminates a few of the earlier 

 applications, for the history of scientific development is also a 

 record of the survival of the fittest. However well rubber, or 

 any other substance, may perform the function required of it, 

 a new process or substitute device may at any time revolutionize 

 the art to which that substance had been applied and so relegate 

 it to the limbo of the past. In photography, for instance, the 

 applications of rubber are gradually but surely diminishing in 

 number. While in a sense regrettable, this side of the rubber 

 industry in any field presents beneficial lessons deserving more 

 than passing thought, and it is in this spirit that the following 

 instances are cited. 



Only two or three years ago most cameras had a rubber bulb 

 and tube to operate the shutter. This equipment had to be re- 

 placed frequently and for the most part has now been replaced 

 by the antinous or flexible cable release which conveys no vibra- 

 tion to the camera yet will last as long as the camera itself. 

 While hard rubber still supplies the leaves and iris diaphragm 

 of many shutters and lenses, as many more now on the market 

 and made of very thin sheet steel are giving satisfaction and 

 have the advantage that they never crack where pivoted. Hard 

 rubber plate-holder slides have for the most part given way to 

 leatherboard and other specially prepared cardboards of smooth, 

 hard surface. These are cheaper and do not become electrified 

 by friction in handling nor attract dust to the plate like hard 

 rubber. Developing trays and tanks of hard rubber are still 

 stocked by most photo-supply dealers, but seem to render no 

 better service than the cheaper receptacles of glass, fiber, agate 

 and artificial stoneware. 



India rubber cloth, by which is meant cotton fabric coated on 

 both sides with a thin film of rubber, still has its photographic 

 uses, although not to the former e.xtent. India rubber focusing- 

 cloths are opaque, as such cloths should be, and are of additional 

 value in protecting the camera during bad weather. Cut pieces of 

 rubber fabric or sheet rubber have long been employed in the 

 printing-frame, back of platinum paper, as a protection from 

 dampness. Once finished, however, a platinum print is a thing of 

 rare beauty and as near absolute permanence as anything known 

 to photography, but the scarcity and high cost of platinum have 

 restricted the use of this medium, and like all sun-printing papers 

 it is gradually giving way to the more easily worked gaslight 

 papers. 



Another printing accessory now rarely seen is the squeegee-pad 

 for glazing prints to a high gloss surface. It consists of a sheet 

 of celluloid placed between two covers of india rubber cloth, the 

 wet prints being applied face down to both sides of the celluloid, 

 the rubber covers brought over them and a roller squeegee be- 

 ing applied over the fabric to bring print and celluloid into close 

 contact for drying. Photographers gradually came to the con- 

 clusion, however, that the rubber sheeting was superfluous, and 

 that the ferrotype tin of today lasts longer, gives a better gloss 

 and is less likely to stick to the print. And here again low first 

 cost also became a contributing influence. 



In photographic processes rubber is holding its own better than 

 in apparatus and accessories, although the amount consumed in 

 the former is inconsiderable. It found favor for a time as a 

 mountant of glazed and dry prints without cockling, a solution 

 being prepared- with carbon disulphide and 5 per cent absolute 

 alcohol. It was discovered, however, that the rubber perishes in 

 time and leaves the mount. 



Pure washed and masticated, unvulcanized rubber was for- 

 merly employed as an edging for wet-plates to prevent the col- 

 lodion coating from leaving the glass, but the faster gelatine dry- 

 plate has superseded its predecessor for all work e.xcept photo- 

 engraving, and is making inroads upon that field as well. 



In the collotype process of ink printing from a specially pre- 

 pared photographic glass positive, india rubber solution is used 

 for attaching to the negative the tinfoil used for masking, but the 

 collotype process has fallen into disfavor to a considerable ex- 

 tent, with the development of half-tone, photogravure and other 

 etching methods. 



In photo-engraving, a solution of india rubber in benzol of 2 

 per cent strength is used for stripping wet collodion films. The 

 collodion negative is flowed with the rubber solution, and when 

 this is dry it is again flowed with stripping-collodion. The rub- 

 ber solution prevents the solvents of the stripping-collodion reach- 

 ing the original collodion film, and at the same time increases 

 the flexibility and toughness of the film. 



India rubber solution continues to be used in aerograph or air- 

 brush retouching because it possesses a distinct advantage over 

 other stopping-out mediums applied to shield certain portions of 

 the print on which the aerograph spray is not wanted. Whereas 

 most other mediums require the application of a solvent for their 

 removal after the spraying has been completed, the rubber film 

 peels off easily upon rubbing with the finger-tip and carries with 

 it any spray that may have spread beyond the desired boundaries. 



Thus the instances cited make it plain, were this necessary, 

 that no primary use of rubber will persist unless rubber in its 

 particular application has important, desirable qualities and dis- 

 tinct advantages peculiar to itself; also that as an accessory its 

 continuance is dependent upon the fate of the device or process in 

 connection with which it is employed. It cannot long compete 

 with substitutes of lower cost which answer the purpose equally 

 well. The big rubber markets will ever be associated with those 

 articles greatly in demand which cannot be manufactured of any 

 other substance. 



DAYTON RUBBER MANUFACTURING CO. BUILDS MODEL PLANT. 



Building operations have begun on the new plant of The Day- 

 ton Rubber Manufacturing Co., Dayton, Ohio. The site com- 

 prises 21 >2 acres of ground, with a frontage on the Pennsylvania 

 Railroad of about 1,500 feet, affording ideal shipping facilities. 

 The main building will be about 500 feet in length and ISO feet 

 in width, part of which will be one story 20 feet high and part 

 three stories, and is so planned that plenty of light will be pro- 

 vided in all parts of the plant, w-hich will be constructed of 

 structural steel, concrete and brick. 



The second story will be used for offices and the third story 

 will be arranged for a large hall for the employes and their 

 friends. The ground not occupied by buildings will be set aside 

 for a ball field, tennis courts, etc., for the benefit of employes. 

 The power plant will occupy a separate building, 70 by 90 feet, 

 and the boilers will all be equipped with stokers to eliminate 

 smoke. 



The Dayton company manufactures both airless and pneumatic 

 tires, and the new plant will have a capacity of 1,000 tires per 

 day. nearly 1.000 men being employed. John A. MacMillan is 

 president and general manager. 



DU PONT COMPANY ACQUIRES HARRISON BROTHERS PROPERTY. 



Through the purchase of Harrison Brothers & Co., Inc.. Phila- 

 delphia, Penn.sylvania, by E. I. du Pont de Nemours & Co., Wil- 

 mington, Delaware, two of the oldest manufacturing concerns 

 in this country have united, the Harrison business dating from 

 1793 and that of the du Pont from 1802. The new corporation 

 conducting the business of Harrison Brothers in chemicals and 

 pigments will be known as Harrisons, Inc., but the or!?anization 

 remains practically the same. 



The Mantua Chemical Co., Camden and Paulsboro, Xew Jer- 

 sey, a part of Harrison Brothers, is also included in the transfer 

 to the du Pont company, the business being continued under the 

 name, Mantua Chemical Co. 



