them extending parallel to
the twine, which thread being cut, they must begin to fall at the
same instant. If they take equal time in falling to the floor, it
is a proof that the resistance of the air is in both cases equal.
If the whole card requires a longer time, it shows that the sum of
the resistances to the pieces of the cut card is not equal to the
resistance of the whole one.
This principle so far confirmed, I would proceed to make a larger
experiment, with a shallop, which I would rig in this manner. (Plate
VI. Fig. 4.)
A B is a long boom, from which are hoisted seven jibs, a, b, c, d,
e, f, g, each a seventh part of the whole dimensions, and as much
more as will fill the whole space when set in an angle of forty-five
degrees, so that they may lap when going before the wind, and hold
more wind when going large. Thus rigged, when going right before the
wind, the boom should be brought at right angles with the keel, by
means of the sheet ropes C D, and all the sails hauled flat to the
These positions of boom and sails to be varied as the wind quarters.
But when the wind is on the beam, or when you would turn to
windward, the boom is to be hauled right fore and aft, and the sails
trimmed according as the wind is more or less against your course.
It seems to me, that the management of a shallop so rigged would be
very easy, the sails being run up and down separately, so that more
or less sail may be made at pleasure; and I imagine, that there being
full as much sail exposed to the force of the wind which impels the
vessel in its course, as if the whole were in one piece, and the
resistance of the dead air against the foreside of the sail being
diminished, the advantage of swiftness would be very considerable;
besides that the vessel would lie nearer the wind.
Since we are on the subject of improvements in navigation, permit
me to detain you a little longer with a small relative observation.
Being, in one of my voyages, with ten merchant-ships under convoy
of a frigate at anchor in Torbay, waiting for a wind to go to the
westward; it came fair, but brought in with it a considerable swell.
A signal was given for weighing, and we put to sea all together; but
three of the ships left their anchors,
But there not being the same contiguity between the particles of air as of water, the solution of water in air is not carried on without a motion of the air, so as to cause a fresh accession of dry particles.Page 22
I take it, that the cloud begins first of all to pour out drops at that particular spot, or _foramen_; and, when that current of drops increases, so as to force down wind and vapour, the spout becomes so far as that goes opaque.Page 122
If that too succeeds, I should think it worth while to make a larger, though at some expense, on a river.Page 123
On these two hooks hang the two bodies, the thread that connects.Page 184
Little fuel serves,.Page 213
when wanted.Page 218
I formerly saw a book printed in the time of queen Elizabeth, which remarked the then modern improvements of living, and mentioned among others the convenience of chimneys.Page 236
5 and 6, each, 0 8Â¼ Breadth of the passage between No.Page 243
After the stove was fixed and in action, I had a pleasure now and then in opening that door a little, to see through the crevice how the flame descended among the red coals, and observing once a single coal lodged on the bars in the middle of the focus, a fancy took me to observe by my watch in how short a time it would be consumed.Page 248
And this will also be the case, when both the opening _before_ the fire, and the funnel _above_ the fire are contracted, provided the funnel above the fire is more contracted in proportion than the opening before the fire.Page 256
Collinson and others, for the generous defence you undertook and executed with so much success, of my electrical opinions; and for the valuable present you have made me of your new work, from which I have received great information and pleasure.Page 257
Between these three are twenty-three different sizes, differing from each other a quarter of an inch in diameter.Page 266
_ [No date.Page 277
| | n |End.Page 290
And it is impossible a reader should give the due modulation to his voice, and pronounce properly, unless his understanding goes before his tongue, and makes him master of the sentiment.Page 293
Thus instructed, youth will come out of this school fitted for learning any business, calling, or profession, except such wherein languages are required: and, though unacquainted with any ancient or foreign tongue, they will be masters of their own, which is of more immediate and general use, and withal will have attained many other valuable accomplishments: the time usually spent in acquiring those languages, often without success, being here employed in laying such a foundation of knowledge and ability, as, properly improved, may qualify them to pass through and execute the several offices of civil life, with advantage and reputation to themselves and country.Page 299
, to those remote regions, which are destitute of them, and to bring from thence such productions, as can be cultivated in this kingdom to the advantage of society, in a ship under the command of Alexander Dalrymple.Page 333
They are both addressed to the judges, but written, as you will see, in a very different spirit.Page 376