290 THE REV. W. YVHEWELL ON TIDE OBSERVATIONS 
Netherlands, twenty-four in Denmark, and twenty-four in Norway ; and observations 
were made by the coast-guard of this country at 318 places in England and Scotland, 
and at 219 places in Ireland. Among the persons who superintended these observa- 
tions on an extensive scale, I have profited in an especial manner by the labours of 
M. Moll, who directed and arranged those made in the Netherlands ; M. Tegner, 
who has performed various reductions on the Danish observations, besides superin- 
tending a large portion of them ; and M. Beautems-Beaupre, who has for some 
years been occupied with valuable hydrographical labours on the coasts of France. 
In several other cases in which the observations have been conducted in a very accu- 
rate and scientific manner, I do not find it stated, in the communications which con- 
tain the registers, under whose general direction the operations were carried on. The 
names of the particular observers will be found in the Tables appended to this memoir. 
I have not used the whole of the observations sent ; as some, from the situation of the 
places, or from other causes, could not be made subservient to my general purpose. 
For instance, I have for the present omitted some, on account of their manifestly 
irregular character ; others, because, being made at some distance up the course of a 
river, they gave no information respecting the tides of the ocean. Such data as these 
last mentioned may still be of use to myself or other investigators on some future 
occasion. 
3. I now proceed to give some account of the general character of these observa- 
tions, the mode employed in reducing them, and the information which they supply 
with respect to the phenomena of the tides. 
The observers were directed to record the times of high water and of low water, 
and the height of the surface at each of these times, measured from a fixed point. 
The time was to be correctly ascertained by the best method which circumstances 
afforded ; and where there was no pier or other permanent scale for the heights, a 
pole was to be erected. Other contrivances, intended to obviate peculiar difficulties, 
need not here be described. The high-water observations were to be considered as 
the most important. 
These directions were for the most part faithfully and effectually followed. The 
observations at different places, made under very different circumstances and by 
persons of different classes, have, as might be expected, very various degrees of 
merit ; but the general relations, both of accordance and discrepance, among the 
observations, convince me that in almost every instance they were conducted with 
care and fidelity. In many of the foreign observations the labour employed in order 
to obtain accurate results has been immense ; and the persons under whose care 
they have been carried on are men of eminent scientific attainments. On our own 
coasts, the nature of the service to which the observers belonged led in many cases 
to the use of ruder methods ; but the processes employed were mostly well selected 
according to the circumstances, and were applied with great practical sagacity. I 
cannot avoid repeating, with respect to the observations of June 1835, what I have 
