THE TIDES. (APP. >.) 221 



ordinarily favourable circumstances as to barometric 

 disturbance, and so would give immediate data for 

 answering, to some degree of accuracy, the question 

 how much does the solid earth really yield to the 

 tide-generating force ? 



10. A year before proposing to Section A of the 

 British Association the appointment of a Com- 

 mittee . to promote tidal investigation, I applied 

 through my friend Staff-Commander Moriarty, 

 R.N., for a year's tidal diagrams of any trustworthy 

 tide-gauge ; and, through his kind assistance, 

 I accordingly received from Staff-Commander 

 Burdwood, R.N., those of the Royal Harbour of 

 Ramsgate for 1864. From the beginning of last 

 winter till the present time I have been engaged 

 in the reduction of these observations, chiefly 

 assisted by Mr. Ebenezer Maclean, but also by 

 Mr. James Smith and Mr. William Ross, students 

 of the Natural-Philosophy Class of Glasgow Uni- 

 versity, last Session, who volunteered to perform 

 the laborious processes of measurement and calcu- 

 lation required. The heights above a certain point 

 near the bottom of the scale, chosen to avoid 

 negative quantities, were measured from the 

 diagrams for noon and midnight 6 P.M. and A.M., 

 3 P.M. and A.M., 9 A.M. and P.M. ; but after some 

 preliminary calculations had shown what valuable 

 results might be expected, the measurement was 

 made for every mean solar hour of the year, and 

 the numbers written down in a book, with a page 



