17, 18, and 19 and spectra 17, U6,/andyd9. ) 
Finally note that the spectra yield very little information 
for periods less than 6 seconds. The depth of location of the 
pressure recorder was 78 feet in one case (B Station) and 103 feet 
for the other case (A Station). Periods less than 5.6 seconds and 
6.5 seconds are hardly detected by the pressure recording instru- 
ment. 
With these qualifications in mind, the records can first be 
studied gualitatively and then compared qualitatively with the 
spectra. Note record 22, for example, in figure A-4. By scanning 
the record, it is seen that the departure from the mean value is 
most of the time much less than the peak values of the record. It 
is not too difficult to accept the hypothesis that enough points 
taken at random would have a Gaussian distribution. Now note 
the tremendous variability of the record as a function of time. 
The time intervals between successive apparent crests vary over 
a wide range. An autocorrelation of the record with itself would 
rather rapidly die down to zero which would mean that what happens, 
say, one minute in the future has very little to do with the be- 
havior of the record at the time of observation. 
Now note record number 6. It is much lower in amplitude, 
but again the departure from the mean of the record is much less 
most of the time than the departure when the few peak values occur. 
Again, it is not too difficult to accept the hypothesis that the 
distribution is Gaussian. The variability of this record is much 
less than that of the former record in that the time interval 
between successive crests is much less variable. An autocorrelation 
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