366 ABSTRACTS OF SCIENTIFIC PAPERS 



wood and agate, was examined at speeds ranging from about 

 O'Ol ft. per second as an upper limit, down to O0002 ft. per second. 

 The axle carried a massive disc, which, once set spinning, was 

 brought to rest by the friction which it was the object of the 

 experiments to measure. The rate of retardation of the disc was 

 determined by means of a pendulum, which swung over against its 

 circumference and traced a sinuous line on a strip of paper 

 fixed to the disc. To avoid friction between the pendulum and 

 the paper, the former was provided with a frictionless marking 

 pointer on the plan invented by Sir W. Thomson for use in his 

 Siphon Recorder for submarine telegraph signals. A fine siphon 

 of capillary glass tube, fixed to the pendulum, and supplied with ink 

 from an insulated cistern, was kept electrified by a small induction 

 machine, and its point was thereby maintained in a continuous state 

 of oscillation towards and from the paper, on which it deposited a 

 particle of ink at every contact. 



When the rubbing surface of the axle and journals was dry no 

 change could be detected in the coefficient of friction throughout 

 the range of velocities experimented on, but when the journals 

 were of wood, and lubricated with water or oil, an increase of fric- 

 tion at the lower limit of velocity was found, amounting to about 

 20 per cent, of the value at the higher limit of velocity. Out of all 

 the sets of circumstances examined a distinct increase of friction 

 with reduced velocity was observed in those, and only in those, 

 cases in which the friction of rest was notably greater than the 

 friction of motion a result which made the hypothesis probable 

 that there is continuity between the two kinds of friction. The 

 method of experiment and the numerical results obtained are detailed 

 fully in the paper. 



XXXII. Remarks on the Phonograph. By Fleeming Jenkin and 

 J A. Ewiiig. ' Proceedings of the Royal Society of Edinburgh,' 

 1878, vol. ix. p. 579. 



XXXIII. On the Wave Forms of Articulate Sounds. By Fleeming 

 Jenkin and J. A. Ewing. (1) ' Proc. R. S. E.,' 1878, vol. ix. 

 p. 582. (2) ' Proc. R. S. E.,' 1878, vol. ix. p. 723. 



XXXIV. The Phonograph and Vowel Theories. By Fleeming 

 Jenkin and J. A. Ewing. (1) 'Nature,' 1878, vol. xvii. p. 423. 

 (2) ' Nature,' 1878, vol. xviii. p. 167. 



XXXV. The Phonograph and Vowel Sounds. By Fleeming Jenkin 

 and J. A. Ewing. (1) The Vowel Sound 6, 'Nature,' 1878, vol. 

 xviii. p. 340. (2) ' Nature,' vol. xviii. p. 394. (3) ' Nature,' 

 vol. xviii. p. 454. 



