latter is but just separated from the fuel, and then moves
only as it is carried by the stream of rarefied air: and without a
continual accession and recession of air, to carry off the smoaky
fumes, they would remain crouded about the fire, and stifle it.
2. Heat may be separated from the smoke as well as from the light, by
means of a plate of iron, which will suffer heat to pass through it
without the others.
3. Fire sends out its rays of heat as well as rays of light, equally
every way; but the greatest sensible heat is over the fire, where
there is, besides the rays of heat shot upwards, a continual rising
stream of hot air, heated by the rays shot round on every side.
These things being understood, we proceed to consider the fire-places
heretofore in use, _viz._
1. The large open fire-places used in the days of our fathers, and
still generally in the country, and in kitchens.
2. The newer-fashioned fire-places, with low breasts, and narrow
3. Fire-places with hollow backs, hearths, and jams of iron
(described by M. Gauger, in his tract entitled, _La Mechanique de
Feu_) for warming the air as it comes into the room.
4. The Holland stoves, with iron doors opening into the room.
5. The German stoves, which have no opening in the room where they
are used, but the fire is put in from some other room, or from
6. Iron pots, with open charcoal fires, placed in the middle of a
1. The first of these methods has generally the conveniency of two
warm seats, one in each corner; but they are sometimes too hot to
abide in, and, at other times, incommoded with the smoke; there is
likewise good room for the cook to move, to hang on pots, &c. Their
inconveniencies are, that they almost always smoke, if the door be
not left open; that they require a large funnel, and a large funnel
carries off a great quantity of air, which occasions what is called
a strong draft to the chimney, without which strong draft the smoke
would come out of some part or other of so large an opening, so that
the door can seldom be shut; and the cold air so nips the backs and
heels of those that sit before the fire, that they have no comfort
till either screens or settles are provided (at a considerable
expence) to keep it off, which both cumber the room, and darken the
fire-side. A moderate quantity of wood on the fire, in so large a
in your hand.Page 10
The same if another gentleman and lady, _C_ and _D_, standing also on wax, and joining hands with _A_ and _B_, salute, or shake hands.Page 13
When both can be done at once, 'tis done with inconceivable quickness and violence.Page 19
Could the water supported by the seven balls come into contact, it would form a drop or drops so heavy as to break the cohesion it had with the balls, and so fall.Page 26
As currents of air, with the clouds therein, pass different ways, 'tis easy to conceive how the clouds, passing over each other, may attract each other, and so come near enough for the electrical stroke.Page 27
_ as so many prominencies and points, draw the electrical fire, and the whole cloud discharges there.Page 28
Till lately we could only fire warm vapours; but now we can burn hard dry rosin.Page 31
So that A will have a redundance of this fluid, which forms an atmosphere round it, and B an exactly equal deficiency.Page 37
) big enough to contain a man and an electrical stand.Page 38
But having no paint at hand, I pasted a narrow strip of paper over it; and when dry, sent the flash through the gilding; by which the paper was torn off from end to end, with such force, that it was broke in several places, and in others brought away part of the grain of the Turky-leather in which it was bound; and convinced me, that had it been painted, the paint would have been stript off in the same manner with that on the wainscot at _Stretham_.Page 41
Take care in cutting your leaf to leave no little ragged particles on the edges, which sometimes form points where you would not have them.Page 47
If you offer a quantity to one end of a long rod of metal, it receives it, and when it enters, every particle that was before in the rod, pushes its neighbour quite to the further end, where the overplus is discharg'd; and this instantaneously where the rod is part of the circle in the experiment of the shock.Page 48
I likewise put into a phial, instead of water,.Page 49
a strong purgative liquid, and then charged the phial, and took repeated shocks from it, in which case every particle of the electrical fluid must, before it went through my body, have first gone through the liquid when the phial is charging, and returned through it when discharging, yet no other effect followed than if it had been charged with water.Page 50
If not, they are not.Page 52
Translated from the Original, dedicated to the French King.