N 



OVEMBER 15, I( 



SCIENCE. 



327 



to the average, it is found in practice that 5ome series will become 

 fully charged sooner than others. 



The details of the methods of use we hope to publish later. Our 

 illustrations show the battery and street-car of the Electric Ac- 

 cumulator Company ; this car, as is well known, calling for no 

 street wires. 



MAGNOLIA-METAL. 

 For the last fifty years the soft metal made of copper, regulus 

 of antimony, and tin, invented by Isaac Babbitt of Boston, and 

 named for him, has been in use for the bearings in machinery, as 

 the friction was much reduced by its use. 



posed to be the best of their class. The machine used was a 5- 

 inch shaft keyed on a 3-inch shaft lubricated with sperm-oil, S-incb 

 shaft running in the oil. With light pressure and slow revolutions 

 of shaft, the metals showed little difference, but, with rapid revolu- 

 tions and heavy pressures, magnolia-metal showed great superiority. 

 The foregoing table shows a detailed statement of the tests, which 

 occupied an hour's time. 



The testing-machine consists of a shaft revolving in suitable 

 bearings, between two of which is a steel journal on which the 

 test-piece is placed ; the top half only of the bearing being used, 

 which was lined with the metals tested. The brass sets in a 

 frame, to the under side of which is suspended a platform. On 



FRICTION TESTING MACHINE. 



Dexjari:Ti:ieiit, Navy Yard, N". Y. 

 Jvve IS. IS.SS. 



FIG. I. —APPARATUS USED IN TESTING MAGNOLIA-METAL. 



In these days of demand for high speed on railways and in 

 ocean steamers, a diminution of the friction is imperative, and 

 magnolia-metal is offered as furnishing a material for bearings 

 much superior to any thing that has gone before. 



Magnolia ran lull time free without melting out or stopping machinery ; Hoyt's 

 melted and stuck to shaft at end of 45 minutes ; de-oxidized genuine Babbitt melted 

 and stuck to shaft at end of 55 minutes. 



Mr. H. G. Torrey, who has been assayer at the United States 

 Mint, New York, for thirty years, has made several friction tests of 

 journal-bearing metals, the results of which have just been made 

 known. Those selected were magnolia-metal, and Hoyt's genuine 

 Babbitt and the de-oxidized genuine Babbitt, the latter two sup- 



this platform the weights are placed for producing the pressure. 

 There are two knife-edges, allowing freedom of the frame, and the 

 weighted platform. A pan beneath the test journal, carrying oil, 

 lubricated the bearing. Thermometers were inserted in the oil- 

 bath and in a recess in the top of the metal. In this machine the 

 co-efficient of friction is obtained by the angle of deviation of the 

 knife-edge from a vertical line passing through the centre of the 

 journal in terms of the radius of the journal, and is independent of 

 the weight entering directly into this calculation. 



Other satisfactory tests have been made by the United States 

 Government at the Brooklyn Navy Yard, and by Professor R. H. 



FIG. 2.— MAGNOLIA-METAL BEARING. 



Smith of Mason College, Birmingham, England, who reports that" 

 his tests show the metal to be superior to either Babbitt or gun- 

 metal, producing less friction, keeping the bearing temperature 

 lower, requiring less lubrication, and possessing greater durability. 

 Professor Smith says that the longer the magnolia-metal bearing is 

 used, and the more severe the duty imposed on it, the better be- 

 comes its condition. 



Recently this new metal has been introduced in the " City of 

 Paris " and the " Augusta Victoria," contributing its share in ther 

 speed developed by these ocean racers. 



