THE TIDES. (APP. D.} 223 



little time as possible in communicating the results 

 to the Committee. I shall keep in view the trial 

 (with which I commenced work on these observa- 

 tions) to find how much of valuable results can be 

 obtained from a comparatively small number of 

 observations, for instance, observations every three 

 hours of the twenty-four, instead of every hour, or 

 every three hours of the day half of the twenty- 

 four, for the purpose of learning how to reduce, as 

 far as possible, the labour and inconvenience im- 

 posed upon those to whom may be committed the 

 execution of observations taken in future according 

 to advice from this Committee. 



II. Probably the best personal observations that 

 have ever been made on the tides are those de- 

 scribed by Captain Sir James Clark Ross, R.N., in 

 the Philosophical Transactions for June, 1854, as 

 having been made by the officers and petty officers 

 of H.M. ships Enterprise and Investigator, every 

 hour of the twenty-four, for nine months, com- 

 mencing November 1st, 1848, in Port Leopold. 

 A full harmonic reduction of these observations, 

 and of the simultaneously observed heights of the 

 barometer, must, as early as possible, be executed 

 by this Committee. 1 



1 This has been performed, and the results have been published 

 in the Report of the British Association, for 1876, p. 289. 



