“And here I must observe, that there have not been wanting persons of considerable name, who have asserted that the velocity of a twenty-four pound bullet was really greater with eight pounds of powder than with any large quantity, founding their opinion on the ridiculous persuasion, that whatever quantity was put in, no more than eight pounds of it took fire; but this supposition is destroyed by their own experiments, and their own reasonings and later experiments, with greater attention, put it beyond all doubt, that to the larger charge (at least as far as twenty pounds of powder) there corresponds a greater velocity.
[4]. It is necessary to observe in this place, that Mr. Muller, whose opinion herein has been confirmed by various experiments, has, with little variation, adopted the sentiments of the above proposal, and strongly recommended them as a scheme of public utility.
[5].
——Yon tall anchoring bark
Diminish’d to her cock; her cock a buoy, &c.
Shakespeare.
[6]. The wires of which the needle has hitherto been generally composed, were only hardened at their ends; now if those ends are not equally hard, or if one end be hardened up higher than the other, when they come to be put together, in fixing them to the card, that end which is hardest will destroy much of the virtue of the other; by which means the hardest end will have the greatest power in directing the card, and consequently make it vary towards its own direction; and, as the wires are disposed in the form of a lozenge, these cards can have but little force; so that they will often, when drawn aside, stand at the distance of several degrees on either side the point from whence they are drawn; for all magnetical bodies receive an additional strength by being placed in the direction of the earth’s magnetism, and act proportionably less vigorously when turned out of it. Therefore when these kind of needles are drawn aside from their true point, two of the parallel sides of the lozenge will conspire more directly than before with the earth’s magnetism, and the other two will be less in that direction: by this means the two former sides will very much impede its return, and the two latter will have that impediment to overcome, as well as the friction, by their own force alone.
[7]. It is necessary to observe here, that the principal, and indeed the only circumstance in which Knight’s compasses are superior to those which have hitherto obtained, is, that their needles being tempered much higher than usual, are thereby enabled to contain a much greater quantity of the magnetical stream, which is certainly a real advantage. But, on the other hand, experience sufficiently proves, and truth obliges us to remark, that the methods he has taken to ballance the card with more accuracy than had been formerly attempted, have rendered it by far too delicate to encounter the shocks of a tempestuous sea.
[8]. “At Java, in the streights of Sunda, when the monsoons blow from the west, viz. in the month of May, the currents set to the eastward, contrary to the general motion.
“Also between the island of Celebes and Madura, when the western monsoons set, viz. in December, January, and February, or when the winds blow from the N W. or between the north and west, the currents set to the S E. or between the south and east.