950 
INDEX. 
Mean density of the earth, determination of, by pendulum experiments, 297 (see Airy) ; deduced 
value, 342, 352, 355. 
Mean specif c gravity of the earth derived from observations at Arthurs Seat (Colonel James), 
606, 609; from the Ordnance Trigonometrical Survey, 607 (Colonel James). 
Megatherium, on the, 571. 
Miller (Professor W. H.). On the Construction of the New Imperial Standard Pound, and its 
Copies of Platinum ; and on the Comparison of the Standard Pound with the Kilogramme 
des Archives, 753. 
O. 
Orhitolites, monograph of the genus, 187 (see Carpenter). 
Owen (Professor). On the Megatherium [Megatherium Americanum, Cuvier and Blumenbach). 
Part III.— The Skull, 571. 
Ozone, on the constitution and properties of, 1. 
P. 
Partition of numbers, 127. 
Pendidum experiments for determining the earth’s mean density, 297 (see Airy). 
Polar-magnet deviations, table of, 83. 
Polarity of the diamagnetic force, 237 (see Tyndall). 
Polyedra, on a class of, 399 ; on the representation of, 413. 
Pound, on the construction of the new imperial standard, 753. 
Pratt (Venerable John Henry). On the Effect of Local Attraction upon the Plumb-line at 
Stations on the English Arc of the Meridian, between Dunnose and Burleigh Moor ; and a 
Method of computing its Amount, 31. — Calculation of the ellipticity of the arc without taking 
account of local attraction, 31; formula for calculating local attraction at any station, 36; 
application of the formula to obtain a rough approximation to the meridian deflection at 
Burleigh Moor, 44 ; Appendix, &c., 48. 
Problem of three bodies, on the, 523. 
Ptychotis Ajowan, chemical examination of, 149; note, 156. 
Q. 
Quantics, 101, 267. 
Quartz pound weight, comparison of, with standard, 894. 
R. 
Rankine (W. J. M.). On Axes of Elasticity and Crystalline Forms, 26. — General definition of 
axes of elasticity, 261 ; strains, stresses, potential energy, and coefficients of elasticity, 262 ; 
thlipsimetric, &c. &c. surfaces and invariants, 264 ; different kinds of isotropy and symmetry, 
269; various transformations, 271 ; on real and alleged differences between the laws of the 
elasticity of solids, and those of the luminiferous force, 282 ; on the action of crystals on 
light, 283. 
Rotifera, on the manducatory organs in the class, 419. 
t 
