466 Scientific Intelligence. 
in which wes — = elastic yielding and frictional resistance 
were first stated a Thus the actual tide at any station in- 
volves two. gost eetnantale fictive x and being the factors by 
which two components, each of the full theoretical height, are to 
_ be multiplied in order give the two components in proper 
amount to represent the r 
If the equilibrium sheort is fulfilled eee sensible elastic 
yielding of the earth, the first component has its full value, or & 
is equal to one, and the second component mee or y is zero. 
If fluid friction exercises a sensible influence, y will have a sensi- 
ble value; and if the solid earth yields tidally, # will be Jess than 
unity. The amount of elastic yielding, and hence the average 
modulus "9 elasticity of the whole earth may be computed from 
the value of x. After rejecting the observations made at certain 
stations for sufficient reasons, I obtained from the Tidal Reports 
of the British Association and from the Indian Tide Tables, the 
results of thirty-three years of observation, made at fourteen 
- different ports in England, France and India 
These cer oy when properly reduced, gave thirty-three equa- 
tions for the- and thirty-three for the y of the fortnightly tide, 
and sintilarly chirty- -three for the w and thirty-three pois the y 0 
the “giant! tide ; in all 132 equations for four unknow 
The x and y 0 of the two classes of tide were in the first instance 
régeeded: as distinct, but the manner in which they arise shows 
that it is legitimate to re egard them as identical, and thus we have 
sixty-six equations for « and sixty-six for y. 
ations were then reduced by the method of least 
squares, with the met ate results :— 
For the rales 
a ore 056, y = 020 + “055 
And for the Loathl tide— 
# = “680 + -258, y = 0904 ‘218 
he numbers given with alternative signs are the probable 
ro 
The @ ver close agreement between the # and y for the two 
tides is probably somewhat due to chance. 
The smallness of the two y’s is satisfactory; for, as above 
stated, if the equilibrium theory were true, they should vanish. 
[oreover, the signs are in agreement with what they should be, 
if friction is a sensible cause of tidal sia But consider- 
ing the magnitude of the probable : is of course of 
likely that the non-evanescence of the ¥ hag to errors 0 
mee rican a p aper on a misprint, disooverod by Professor Adams, 
in the “tidal report for 1872. This report forms the basis of 
