536 



INDEX. 



meters, on a mechanical device for 

 performing- the, 403. 



Temperatures at great depths, on 

 underground, 78 ; on the determi- 

 nation of high, with the mel- 

 dometer, 360. 



Thermal conductivities of cements, 

 &c, on a simple apparatus for 

 determining the, 495. 



Thermodynamic properties of air, on 

 the, 288. 



Thermo-electric interpolation for- 

 mulae, on, 465. 



Thermometer, on a direct reading 

 platinum, 62; on an electric, fol- 

 low temperatures, 312. 



Thomson (Prof. J. J.) on electrified 

 atoms, 151. 



Tinfoil-grating detector for electric 

 waves, on the, 445. 



Tones, on resultant, 199. 



Trowbridge (Prof. J.) on carbon and 

 oxygen in the sun, 450 ; on trian- 

 gulation by means of the cathode 

 photography, 463. 



Valenta (E.) on the spectra of argon, 

 149. 



Vandevyver (L.-N.) on a new areo- 

 meter, 530. 



Wadsworth (F. L. O.) on a simple 

 and accurate cathetometer, 123 ; 

 on Mr. Burch's method of drawing 

 hyperbolas, 372. 



Wave-form, on the effect of, on the 

 alternate-current arc, 507. 



Wheatstone bridge, on an addition 

 to the, for the determination of 

 low resistances, 414. 



Wiesener (Prof. T.) on tropical rain 

 148. 



Witkowski (A. W.) on the thermo- 

 dynamic properties of air, 288. 



Wood (E. M. R.) on the Llandovery 

 and associated rocks of Conwav, 

 147. 



Wood (R. W.) on the dissociation 

 degree of some electrolytes at 0°, 

 117 ; on the duration of the flash 

 of exploding oxyhydrogen, 120 ; 

 on a duplex mercurial air-pump, 

 378 ; on focus tubes for producing 

 .r-rays, 382 ; on the absorption 

 spectrum of soliuVons of iodine and 

 bromine above the critical tempe- 

 rature, 423. 



X-rays, on focus tubes for producing, 

 382. 



END OF THE FORTY-FIRST VOLUME. 



Printed by Taylor and Francis, Red Lion Court, Fleet Str eet. 



