The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science

670

THE

LONDON, EDINBURGH, AND DUBLIN

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

CONDUCTED BY

SIR ROBERT KANE, LL.D. F.R.S. M.R.I.A. F.C.S.
SIR WILLIAM THOMSON, KNT. LL.D. F.R.S. &c.

AND

WILLIAM FRANCIS, PH.D. F.L.S. F.R.A.S. F.C.S.

"Nec aranearum sane textus ideo melior quia ex se fila gignunt, nec noster
vilior quia ex alienis libamus ut apes." JUST. Lips. Polit. lib. i. cap. 1. Not.

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Meditationis est perscrutari occulta; contemplationis est admirari perspicua. . . . . Admiratio generat quæstionem, quæstio investigationem, investigatio inventionem."-Hugo de S. Victore.

Cur spirent venti, cur terra dehiscat,

Cur mare turgescat, pelago cur tantus amaror,
Cur caput obscura Phoebus ferrugine condat,
Quid toties diros cogat flagrare cometas ;
Quid pariat nubes, veniant cur fulmina cœlo,
Quo micet igne Iris, superos quis conciat orbes
Tam vario motu."

J. B. Pinelli ad Mazonium.

CONTENTS OF VOL. XLVIII.

(FOURTH SERIES.)

NUMBER CCCXV.-JULY 1874.

Page

Prof. R. Clausius on different Forms of the Virial..

Mr. F. P. Purvis on Amsler's Planimeter

Prof. A. W. Wright on the Polarization of the Zodiacal Light.

Baron N. Schilling on the Constant Currents in the Air and

in the Sea: an Attempt to refer them to a common Cause..

Mr. R. Mallet on the Tidal Retardation of the Earth's Rotation.

Mr. E. W. Hilgard on some points in Mallet's Theory of Vul-