November 8, 1895. ] 



SCIENCE. 



621 



terinary College, superintends a veterinarj' 

 service attached to tlie Institute. The In- 

 stitute, opened in 1888, will continue its 

 activitj'- under the same constitution as 

 under its late chief. 



THE PHENOMENA OF FRICTION. 



M. Raffaed has extracted from the tech- 

 nological publications of the Societe des 

 Anciens JEleves des Ecoles nationale d'Arts et 

 Metiers, August, 1895, a paper* in which 

 he summarizes the earlier work of Amou- 

 tons (1699), of Coulomb (1781) and of 

 Morin, Krest and Haton de la Goupilliere 

 in our own times, and proceeds to the dis- 

 cussion of his own recent experiments, par- 

 ticularly on the friction of cords and belts 

 on pulleys and cylinders about which they 

 ma J' be wrapped. As early as 1880 he had 

 noted the fact that the friction of such 

 flexible wrapping connections was very 

 slight at low velocities rapidly increasing 

 with acceleration of speed, and had pre- 

 sented the results of his work to the Society 

 (Trans. 1880, p. 671). The experiments of 

 Holman (Jour. Franklin Institute, Sept. 

 1885) confirm his own conclusions. Giving 

 Holman's graphical illustration of the rela- 

 tion of friction of slipping belts to speeds, 

 he makes the following final deductions : 



1. In sliding friction the relative motion 

 of the bodies is in line of the resultant of 

 the applied forces. 



2. With rolling friction the resistance 

 remains substantially the same as when 

 starting from rest, both in the plane of ro- 

 tation and transversely to that plane, and 

 a wheel will roll in its own plane, until the 

 adherence is broken either by lateral or 

 by circumferential stress, when it will at 

 once take up a line of motion corresponding 

 to the resultant of the acting forces. 



3. The coefficient of friction of belts on 

 * Considerations sur les Pli(5nomenes du Frotte- 



ment, N. J. Raffard, Paris, 1895. Pamphlet mono- 

 graph. Pp. 15, 4. 



turned and polished pulleys is at starting 

 and at low velocities but about one sixth its 

 magnitude at high speeds of relative mo- 

 tion. 



GENERAL. 



A BiOGEAPHY of Huxlcy is being pre- 

 pared by his son, Mr. Leonard Huxley. Na- 

 ture states that Mr. Huxley will be .greatly 

 obliged if those who possess letters or other 

 documents of interest will forward them to 

 him at Charter House, Grodalming. They 

 will be carefully returned after having been 

 copied. 



De. Heebeet H. Field, whose address 

 at present is 67 Rue de Bufifon, Paris, an- 

 nounces that arrangements have just been 

 made with Engelmann, of Leipzig, for a 

 ' Bibliographia Zoologica,' and with Fischer, 

 of Jena, for a ' Bibliographia Anatomica.' 

 The former will be sold in book form an- 

 nually at $3.75, while in the card form it 

 will be issued at the rate of $2.00 per thou- 

 sand cards. Dr. Field announces that it is 

 necessary to secure 75 subscriptions to the 

 Bibliographj^j in book or card form, in the 

 United States. This will be the most com- 

 plete and systematic bibliography which 

 has ever been issued, and deserves the 

 prompt and generous support of zo51ogists 

 in all parts of this country. Subscriptions 

 should be addressed directly to Dr. Field. 



The Indian Engineer, a journal which 

 has been published for quite a number of 

 years in Calcutta, has recently changed its 

 name to The Indian and Eastern Engineer, 

 and extended its scope accordingly. Its 

 object is to make engineers in the East 

 acquainted with the best methods, Ameri- 

 can, English and Continental, employed in 

 the industrial arts. Publications and arti- 

 cles descriptive of the arts and industries 

 will be gladly received by the editor for 

 republication in his journal. The editor 

 of this journal is C. W. Merton, 1S7 Cannings 

 Street, Calcutta, India. 



