132 
SIR Gr. B. AIRY ON THE TIDES AT MALTA. 
The purport of the deductions from these computations will be more distinctly 
seen on taking the means for each eighth part of the lunation. This operation, which 
required for the means the subdivision of each 7 days period into two' equal parts of 
3^ days each, was thus performed : — The mean of days 1, 2, 3 was taken, and the 
mean of days 1, 2, 3, 4 was taken, and the mean of these two means was adopted as 
the fitting mean for the first subdivision of 3-g- days. Then the means of days 
4, 5, 6, 7 and of days 5, 6, 7 were taken, and their mean was adopted as mean for the 
second subdivision of 3-| days. 
