Part 21 (1/2)
The bulb of a tulip in every respect resembles buds, except in their being produced under ground, and include the leaves and flower in miniature, which are to be expanded in the ensuing spring. By cautiously cutting in the early spring, through the concentric coats of a tulip root, longitudinally from the top to the base, and taking them off successively, the whole flower of the next summer's tulip is beautifully seen by the naked eye, with its petals, pistal, and stamina.
_The Travelling of Sound experimentally proved._
There is probably no substance which is not in some measure a conductor of sound; but sound is much enfeebled by pa.s.sing from one medium to another. If a man, stopping one of his ears with his finger, stop the other also by pressing it against the end of a long stick, and a watch be applied to the opposite end of the stick, or a piece of timber, be it ever so long, the beating of the watch will be distinctly heard; whereas, in the usual way, it can scarcely be heard at the distance of fifteen or eighteen feet. The same effect will take place if he stops both his ears with his hands, and rest his teeth, his temple, or the gristly part of one of his ears against the end of a stick. Instead of a watch, a gentle scratch may be made at one end of a pole or rod, and the person who keeps his ear in close contact with the other end of the pole, will hear it very plainly. Thus, persons who are dull of hearing, may, by applying their teeth to some part of a harpsichord, or other sounding body, hear the sound much better than otherwise.
If a person tie a strip of flannel about a yard long, round a poker, then press with his thumbs and fingers the ends of the flannel into his ears, while he swings the poker against an iron fender, he will hear a sound very like that of a large church bell.
_To produce Metallic Lead from the Powder._
Take one ounce of red lead, and half a drachm of charcoal in powder, incorporate them well in a mortar, and then fill the bowl of a tobacco-pipe with the mixture. Submit it to an intense heat, in a common fire, and when melted, pour it out upon a slab, and the result will be metallic lead completely revived.
_To diversify the Colours of Flowers._
Fill a vessel of what size or shape you please, with good rich earth, which has been dried and sifted in the sun, then plant in the same a slip or branch of a plant bearing a white flower, (for such only can be tinged,) and use no other water to water it with, but such as is tinged with red, if you desire red flowers; with blue, if blue flowers, &c. With this coloured water, water the plant twice a day, morning and evening, and remove it into the house at night, so that it drink not of the morning or evening dew for three weeks. You will then experience, that it will produce flowers, not altogether tinctured with that colour wherewith you watered it, but partly with that, and partly with the natural.
_How far Sound travels in a Minute._
However it may be with regard to the theories of sound, experience has taught us, that it travels at about the rate of 1142 feet in a second, or nearly thirteen miles in a minute. The method of calculating its progress is easily made known: when a gun is discharged at a distance, we see the fire long before we hear the sound; if, then, we know the distance of the place, and know the time of the interval between our first seeing the fire, and then hearing the report, this will show us exactly the time the sound has been travelling to us. For instance, if the gun be discharged a mile off, the moment the flash is seen I take a watch and count the seconds till I hear the sound; the number of seconds is the time the sound has been travelling a mile.
_Easy Method of making a Rain Gauge._
A very simple rain gauge, and one which will answer all practical purposes, consists of a copper funnel the area of whose opening is exactly ten square inches: this funnel is fixed in a bottle, and the quant.i.ty of rain caught is ascertained by multiplying the weight in ounces by 173, which gives the depth in inches and parts of an inch.
In fixing these gauges, care must be taken that the rain may have free access to them: hence the tops of buildings are usually the best places. When the quant.i.ties of rain collected in them at different places are compared, the instruments ought to be fixed at the same heights above the ground at both places, because at different heights the quant.i.ties are always different, even at the same place.
_To make beautiful Transparent coloured Water._
The following liquors, which are coloured, being mixed, produce colours very different from their own. The yellow tincture of saffron, and the red tincture of roses, when mixed, produce a green.
Blue tincture of violets, and brown spirit of sulphur, produce a crimson. Red tincture of roses, and brown spirits of hartshorn, make a blue. Blue tincture of violets, and blue solution of copper, give a violet colour. Blue tincture of cya.n.u.s, and blue spirit of sal-ammoniac coloured, make green. Blue solution of Hungarian vitriol, and brown ley of potash, make yellow. Blue solution of Hungarian vitriol, and red tincture of roses, make black; and blue tincture of cya.n.u.s, and green solution of copper, produce red.
_Curious Experiment on Rays of Light._
That the rays of light flow in all directions from different bodies, without interrupting one another, is plain from the following experiment:--Make a little hole in a thin plate of metal, and set the plate upright on a table, facing a row of lighted candles standing near together; then place a sheet of paper or pasteboard at a little distance from the other side of the plate; and the rays of all the candles, flowing through the hole, will form as many specks of light on the paper as there are candles before the plate; each speck as distinct and large as if there were only one candle to cast one speck; which shows that the rays do not obstruct each other in their motions, although they all cross in the same hole.
_The Power of Water._
Let a strong small iron tube of twenty feet in height be inserted into the bung-hole of a cask, and the aperture round so strongly closed, that it shall be water-tight; pour water into the cask till it is full, through the pipe; also continue filling the pipe till the cask bursts, which will be when the water is within a foot of the top of the tube. In this experiment the water, on bursting the vessel, will fly about with considerable violence.
_The Pressure of Water._
The pressure of water may be known to every one who will only take the trouble to look at the c.o.c.k of a water-b.u.t.t when turned: if the tub or cistern be full, the water runs with much greater velocity through the c.o.c.k, and a vessel will be filled from it in a shorter time than when it is only half-full, although the c.o.c.k, in both cases, is equally replete with the fluid during the time the vessel is filling.