464 SEVENTH REPORT—1837. 
error, from which the “ corrected statical level’”’ is derived by a 
correction obtained from observation. 
The modes of generating the fluid were very numerous, but 
as the resulting phenomena of the waves were found to be inde- 
pendent of the mode of generation, a sufficient number only are 
given to establish the means of comparison. These extend from 
Wave I. to Wave XXV. Those waves “created by reservoir 
A” were formed by filling that portion of the channel at the 
end of the experimental channel of Plate I. with a given volume 
of water, which was added to the water in the channel by the 
sudden removal of the sluice S, and so formed the wave. The 
waves ‘‘ generated by impulsion” of sluice were formed by 
placing the sluice at the back of reservoir A, and suddenly bring- 
ing it to the front of the reservoir, so as to communicate a hori- 
zontal impetus to the fluid forming the wave. The waves 
“generated by detached chamber B”’ were formed by placing 
the rectangular vessel B, Plate I., at the end of the reservoir and 
filling it with water to a given volume: by raising the sides of 
this vessel from the bottom of the reservoir, the column of water 
was allowed to descend by gravity and generate the wave. 
Column A contains the number of feet described by the wave 
from the commencement of the observations. 
Column B contains the interval of time given by two observers 
and two chronometers, « and 6: these intervals of time corre- 
spond to the spaces in column A. 
Column C contains the observations of height of the wave 
made in two sets of glass indices—index y near the end B of 
the experimental channel, and index 8 near the end D, Plate I. 
Column D contains the heights of the waves at y and 4, freed 
from error of scale. 
Column E contains the sum of the corrected height of the wave 
and of the corrected depth of the fluid, taken from a mean of 
the observations. 
