played throughout the work; as an instance of this, I may mention that after they had been labouring from six o'clock on Saturday morning until ten at night, seeing that a few more hours of work would complete the roofing in, they entreated permission to finish it before they left off; but as it would have broken in upon the Sabbath morning, their request was very properly refused: this is only one of several such instances of their disinterested zeal in the cause, for, from their unfortunate situation, they could not derive any benefit from their additional labour, and must have, on the occasion above mentioned, suffered much fatigue from their unusually prolonged exertions.
By these means we were enabled to begin the observations at this station some months earlier than we could have done under ordinary circumstances, and much sooner than I could have possibly anticipated. The ships' portable observatories had also been put up at convenient distances from the permanent observatory; and by the aid of some volunteer assistants we obtained a very complete and satisfactory series of observations throughout the 27th and 28th of August, with two sets of magnetometers, in which the three instruments of each were simultaneously recorded at every interval of two and a half minutes throughout the twenty-four hours.
The great advantage of obtaining the readings of all three instruments at each interval over the