ON AN EXPEDITION FOR TIDE OBSERVATIONS. 135 
tain a great body of facts of this kind. The observers would, of course, 
observe the facts of the tides in connexion with each other; and would 
arrange tbeir plan of operation so as to extend their lines of connexion from 
known poinfa to unknown. By such a mode of proceeding the cotidal lines 
for every part of the Pacific and Indian Oceans might pnibably bo drawn 
(omittiDg the minor details in the interior of archipelagos, &c.) in a year, or 
at most, in two years. 
The tide observations made at tlie rei^uest of Dr. Whewe.ll in 18.’I4 for a 
fortoigbt by the coast-guard on the coasts of Great Britain and Ireland, prove 
how great an accession our tidal knowledge may receive from connected ob¬ 
servations; and still more those made in June 1835 for a fortnight along the^ 
oasts of the whole of Europe and the eastern coast of the United States ot 
Xorth America. By means of these observatituis the general course of the 
tides in the seas thus explored has been determiued. 
If an expedition were sent for the purpose of making tide observations, it 
would not be at all necessary to have, as in the instances just mentioned, 
simultaneous observations along tlie whole line of sea observed. U would 
Suffice to connect a few places by corresponding observations, in some cases 
for a fortnight, iu others for a few days; then, to connect one of these places 
with others, ami thus to proceed through the w hole region observed. 
It appears by tiic experience of the surveys which we have n-ferred to, 
that the observations may be made by sailors such as those employed on the 
coa»t-guard, under proper directions. On those occasions the necessary appa¬ 
ratus was speedily constructe<l by the persons employed. It might however 
he useful also to employ, in several places, self.regbitoring tide-gauges, such 
M are already established in several English ports. 
We conceive that the project conteniplattid by the Association in its recom¬ 
mendation is very desirable 5 and might best bo attaitied bv i^ntling out a 
vpael which sliould have for the object of its voyage to maKc tide observa¬ 
tions upon such a oonnected system. For this purpose, the vessel ought to 
carry, in addition to a crew Bufticieul to work her, ten or fifteen men, who by 
tliemselves (in pairs), or under the direction of petty oflicers, might be trusted 
to make tide observations fur a week or a fortnight at selected points of coast. 
The surveying vessel ought to bo provided with a launch, to be employed in 
carrying these observers to their station, visiting them while engaged in their 
*ork, nr fetching them away when their task at each place is done. From 
one region to anotlier of fl?^ ocean, btaudard sbitiona ought to be selected, at 
vhich tide observations should be continued for a longer time, and the ob¬ 
servations made in each region should lie compared with those atthestandard 
•tetioii. The comparison of the observations with each other, as the survey 
proceedf-d, would point out the dlrecUuD in which it was dcsimble to extend 
the survey, and the special points to be attended to. We therolore recom¬ 
mend tbat application bo made to the Admiralty that they would appropriate 
to this service a suitable vessel. 
