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SCIENCE 



LEiuered at the Posr-Ollice o£ New York, N.Y., as Second-Class Maiter.J 



A WEEKLY NEWSPAPER OF ALL THE ARTS AND SCIENCES. 



Sevknth Year. 

 Vol. XIV. No. 356 



NEW YORK, November 29, li 



Single Copies, Ten Cents. 

 ^3.50 Per Year, in Advance. 



THE TRIPP ANTI-FRICTION ROLLER-BEARING. 



This bearing is adapted for use on car axles, dynamo-shafts, 

 and similar places where there is high speed or heavy pressure, or 

 both. It consists of a double set of rollers held in place by a sort 

 of skeleton frame, and enclosed in a box of suitable construction. 

 The rollers are of steel, of ihe same degree of hardness as when 

 cut from the bar. They fit snugly around the shaft or axle, and 

 bear against the inside of the box, revolving on their axes, and 

 travelling around with the shaft, thus reducing the friction to 

 almost zero, or, in other words, to rolling friction. Mr. J. A. 

 Dyblie of the Chicago Arc Light and Power Company turned a 

 six-inch shaft with his thumb and finger to and fro with the 

 greatest ease. 



The construction of the device may easily be understood by an 

 inspection of the accompanying illustrations. Fig. i is a perspective 

 view, with part of the outer shell or box broken away to show the 

 interior, and one of the rollers removed to show the pin upon which 

 it revolves. This pin, it must be remembered, performs no duty 



the bearing is made dust-proof by a cap at one end and an expan- 

 sive packing at the other, which, it is claimed, keep the lubricating 

 material absolutely free from dust and water, so that it does not 

 require renewal during the life of an ordinary chilled car-wheel. 



Another advantage claimed is, that, when the brake is strongly 

 applied, the strain comes on the rolls opposite the brake-shoe, 

 causing no cramping, the axles turning as freely in the boxes as 

 ever. In ordinary bearings the tendency is to crowd the journal 

 out of the brasses, thereby reducing the bearing surface, inducing 

 a tendency to heat when the journal returns to the centre of the 

 box upon the release of the brake. 



In a test of a two-inch journal in one of these bearings, under a 

 pressure of four hundred pounds, without lubrication, it made a 

 record of six thousand revolutions a minute for two hours without 

 heating. Under a five-thousand-pound street- car, holding the 

 regular number of passengers, a set of these bearings has been in 

 use over two years with only one lubrication: and, though the car 

 has been off the track the usual number of times, the bearings show 

 no detrimental wear. They are now doing good service on about 



ROLLER-BEARINGS FOR REDUCING FRICTION. 



except to keep the roller in place when the shaft is removed, and to 

 keep the roller in line with the shaft when in use. It bears no part 

 of the weight of the shaft or axle, that all being transferred to Ihe 

 box by the rollers. Fig. 2 is a sectional view of the bearing, show- 

 ing a very important feature ; namely, the thrust-plate and collars, 

 which take the end-thrust of the axle caused by the side-motion of 

 the cars, as in going around a curve. This feature is shown at the 

 left of the sectional view. The thrust-plate is bolted firmly to the 

 box, and has two leatheroid collars — one on each side — between 

 it and the thrust-collars, which latter are keyed to the end of the 

 axle. This thrust-bearing has an area of sixty-three square inches, 

 in contact at both ends of the car-axle, while that of the master 

 car-builders' standard axle has an area of only seventeen square 

 inches, in contact at only one end of the axle at a time. 



It is stated, that, in a set of these bearings on a train running be- 

 tween Boston and Philadelphia, the rollers show a reduction in 

 diameter of less than five one-thousandths of an inch, after a total 

 service of forty-five thousand miles. They also remain uniform in 

 size from end to end. This shows a very small amount of friction. 

 Much of the long life of these rolls is doubtless due to the fact that 



twenty street-cars, and are being applied to electric car-motors, 

 stationary motors, shafting, and in various other places where a 

 minimum of friction is desired. 



FUNGOUS DISEASES OF PLANTS. 



Various rusts, smuts, mildews, blights, and similar diseases of 

 cultivated plants, have been generally known and dreaded since 

 plants began to be cultivated. Any understanding of the cause of 

 these troubles-, of the conditions of their occurrence, and of their 

 relations to each other and to the plants they infest, is a matter of 

 comparatively recent acquisition even among botanists. Among 

 American farm&rs and gardeners it is only recently that intelligent 

 inquiry and thought regarding these important sources of loss have 

 been awakened, and they are but just beginning to be popularly 

 spoken of as fungous diseases. With this increased popular inter- 

 est has naturally arisen an increased interest in their scientific in- 

 vestigation, which is as yet but fairly begun, and in the practical 

 application of our technical knowledge in devising ways and means 

 for checking the spread and preventing the ravages of the pests. 



