XVI ROYAL SOCIETY OF CANADA 
kindness of the admiralty this record was obtained. It should be utilized 
to extend the basis from which the tide-tables for Halifax are calculated, 
as they now depend on the record taken during two years only, namely, 
1860 and 1861. The comparatively small outlay required for this pur- 
pose cannot be made at present, however. Since 1891 the tide-tables for 
Halifax have been issued annually by this department in the form of a 
small booklet. Its circulation has not been large, and, after correspond- 
ence with book-sellers in this country and in Britain with a view to 
extending its usefulness, it was eventually decided to supply the tables 
for publication in two lower province almanacs. The tables are accom- 
panied by tidal differences which make them available for the whole 
Atlantic coast of Nova Scotia. 
“ At present the record at Quebec and St. John, N.B., is nearly sufti- 
cient for the calculation of preliminary tide-tables for these ports. At 
places where the range of the tide is so great, these tables should show 
the rise and fall of the tide, as well as the times of high and low water. 
At Quebec the rise and fall can be referred to the original low water 
datum of the admiralty charts ; as the reference bench-mark still exists 
which was cut on the building of the department of marine at the time 
the admiralty surveys were made. At St. John, N.B., there is no bench- 
mark or other level from which to ascertain with certainty the low water 
datum adopted in the admiralty surveys, or in the more recent surveys 
of the harbour made by the department of public works. It is specially 
important at St. John to have a correct low water datum, not only in the 
interests of navigation and for such purposes as the construction of slips for 
repair of vessels, but also because properties are often defined by the low 
water line. In the absence of any permanent mark to record the results 
which were before obtained, the only course to take was to commence 
the work again. A bench-mark was accordingly established on the foot- 
ing course of the new custom-house building; and for further security 
its level was also connected with the foundation course of the post-oftice. 
To this bench-mark the rise and fall of the tide is now referred, and a 
satisfactory low water datum will thus in time be obtained. 
‘Survey of the Currents. 
“ It was considered most important at the outset to ascertain the 
nature of the currents at the two main entrances to the Gulf of St. Law- 
rence, namely, in the Strait of Belle Isle and Cabot Strait, between Cape 
Breton and Newfoundland. The most satisfactory plan would have been 
to place a surveying vessel in each of these straits, to obtain simultane- 
ous observations over a longer period of time. This could not be arranged 
for want of means, and the best that could be done was to set apart the 
steamship ‘Lansdowne’ for three months in which it could be spared 
with least inconvenience from its other duties. It was accordingly de- 
