N° VI. 
TABLE OF DAYS’ WORKS KEPT ON BOARD THE HECLA. 
In the following Table, the courses and distances from day to day 
are those deduced from observation, whenever any was obtained. The 
common Log made use of in keeping the Dead Reckoning, was marked 
with forty-eight feet to the knot, and the glass adjusted to run twenty- 
eight seconds. When the ship was sailing, however, upon one course 
for several hours together, Massey’s Patent Log was used in preference ; 
this invaluable machine was also much made use of, in running bases for 
the survey. 
The greatest care was taken in correcting the courses steered by compass, 
for the Variation on each direction of the Ship’s Head, and for the leeway 
or drift. The former correction was easily obtained by the habit of in- 
variably observing, morning and evening, by the Sun’s Azimuth, whenever 
that object was visible. By thus attending minutely to the reckoning, it 
was my particular wish to ascertain whether any general current exists 
in that part of the Atlantic included between the Shetland Isles, and the 
entrance to Davis’ Strait. By a comparison of the ship’s place as deduced 
from the Dead Reckoning, and that determined by Observation in the months 
of May and June 1819, a considerable southerly set is perceptible in crossing 
the Atlantic from the Orkneys to the meridian of Cape Farewell, the error 
in southing exceeding that in northing by thirty-six miles. This current 
may be observed in a slight degree daily (with one exception) from the 22d 
to the 27th of May, between the meridians of 7° and 24° west, amounting in 
more than one instance, to between eight and nine miles per day ; after 
this, the ship appears to have been set somewhat to the northward while 
under the lee, as it were, of Iceland, till she had reached the 34th degree of 
longitude, immediately to the westward of which, the error in southing was 
from seven to tw'enty miles for each of three successive days. This latter 
set was also perceptible, with a few exceptions arising perhaps from unavoid- 
