Thanks WT for paper on rigidity of the earth; agrees tidal action affects not only fluid motion of earth, but the solid as well. Mentions JH's paper of the previous year suggesting that tidal waves cause earthquakes. Raises questions about the idea of the earth as a magnet and about WT's dynamical theory of heat.

Thanks WT for pageproofs of his work on analytical dynamics. Compliments work on Isaac Newton's view of nature of luminous ether. Gives own views on ether and motion theory of heat.