The best way to do this is to use a number ofblowpipe flames directed downward.
You see its power when I place a bundle of iron wire in the flame; it is, in fact, a concentration of hundreds or thousands of powerful blowpipe flames in one mass.
The thousands of uses to which blowpipes are adapted are so well known, that they need no mention, except the curiously ignored fact that the power of any blowpipe depends on the air pressure.
A blowpipe may also be used with good effect, as shown in the above engraving, and in many cases it is preferable and much easier to manage.
In this angle, underneath, is directed a very fine blowpipe flame on one spot, and the hands are passed singly over this spot until the color comes, when they are instantly pushed over the edge.
A very neat repair can be made with an alcohol lamp and a blowpipe by using a little silver solder.
I always keep this blowpipe burning, as the gas it consumes is very small, and the burner is kept within easy reach by using a hanger, as shown in the illustration.
A small blowpipe is often a valuable adjunct, as it makes possible a long, narrow flame that may be directed in almost any direction.
Illustration] He should also practise using the blowpipe until he can keep up a steady and uninterrupted flame for ten minutes or a quarter of an hour, without stopping for breath.
The blowpipe is to the artist and the experimentalist what the wind-furnace is to the artisan; but it is proportionately more powerful, convenient, and economical.
Used in soldering, and as a flux, particularly in blowpipe experiments.
LARGE TUBES require the heat of a powerful blowpipe and lamp, or that of a furnace.
Charcoal varies in its qualities according to the substance from which it is prepared: that of the soft woods (willow or alder) is best for crayons and gunpowder; that of the hard woods for fuel, and for blowpipe supports.
Illustration] A simple and inexpensive apparatus for supplying a continuous blast of air for blowpipe or other purpose is figured below.
The principal varieties of the blowpipein general use are figured in the engravings above.
Through a blowpipe or quill inserted into the glottis blow air into the trachea and observe the inflation of the lungs and of certain large air-sacs in the abdomen, which communicate with them.
Insert a blowpipe or quill into the glottis just back of the tongue, and inflate the lung, which is a long, thin-walled bag extending from the region of the heart posteriorly for two-thirds of the length of the body.
Blow with a simple bent blowpipe with point smaller than the hole.
Insert a blowpipe into the glottis and inflate the lungs, which will fill all the otherwise unfilled space in the thoracic cavity.
Inflate the oesophagus with a blowpipe and note how distensible is its lower end near the breast.
Before the blowpipe with sodium carbonate on charcoal, solid Sb compounds give a grey brittle globule of the metal and a white incrustation.
Heated with the blowpipeon charcoal it gives white fumes of oxide, without odour (arsenic gives a garlic odour).
Before the blowpipe the mineral readily fuses with intumescence to a colourless glass.
Alumina itself is so refractory that it cannot be melted save by the oxyhydrogen blowpipe or the electric arc, and except in the molten state it is not susceptible of decomposition by any chemical reagent.
Soldering, brazing and the blowpipe in the Cordilleran provinces are suspected, but the evidence of their existence must be further examined.
As it burns at the end of the nozzle it is broken into carbon and hydrogen--the carbon gives the high temperature, and the hydrogen forms a cone that protects the end of the blowpipe from being itself burnt up.
This raid may cost a couple of dollars, as far as the blowpipe is concerned--quite a difference from the thousands of dollars' loss that would follow an attempt to blow the door in.
Minute after minute sped by, as the line burned by the blowpipe cut straight from top to bottom.
The best thing about this style of blowpipe is the ease with which it can be transported and the curious uses--like the present--to which it can be put.
Almost as he said it, the steel beneath the blowpipe became incandescent.
The blowpipe is no longer an instrument for joining metals together, but for cutting them asunder.
When lead-glass is to be used, the blowpipe flame should be in good adjustment and the glass should not be allowed to approach so near to the blue cone as to be blackened.
The whole source of the flame should be mounted on a separate base, in order that it may be moved while adjusting the apparatus to the best relative positions of flame and blowpipe jet.
The final closure is made by melting the drawn-out extension in the blowpipe flame; the finished seal being shown by g, Fig.
The usual, or Herepath, type of gas blowpipe consists of an outer tube through which coal gas can be passed and an inner tube through which a stream of air may be blown.
Now rotate the cracked portion of the outer bulb in front of a blowpipe flame and press the halves together very gently as the glass softens.
As a rule it is harder than ordinary soda-glass, and less suitable for working in the blowpipe flame.
This may be worked more easily if a small percentage of oxygen is introduced into the air with which the blowpipe flame is produced.
Such a glass is not very suitable for use with the blowpipe owing to the difficulty experienced in obtaining a sufficiently high temperature.
The blowpipe jets, of which there may be several with advantage, may be made of glass tubing, bent to the most convenient angle and having an enlargement or bulb at some point in the tube.
If the air is replaced entirely by oxygen there is a risk of damaging the blowpipe jet, unless a special blowpipe is employed.
This, in addition to being a valuable exercise in manipulation, will teach him to keep his blowpipe in good order, and prove a useful aid in his early efforts to judge as to the condition of the flame.
Nowadays one can purchase cheaply a very effective portable plant, or after a few lessons a man may by practice make himself so proficient with the blowpipe as to obtain assay results sufficiently accurate for most practical purposes.
The Blowpipeand Crucible and their Technical Equivalents.
Most silver ores are easily recognisable, and readily tested by means of the blowpipe or simple fire assay.
If the object is of considerable size it is most conveniently heated on the forge; if small the blowpipe is more convenient.
It is generally old, and this kind of glass often devitrifies with age, and is then useless for blowpipe work, though it may be bent sufficiently for assembling chemical apparatus.
However carefully a tube is cleaned before being subjected to blowpipe operations, it will be fouled wherever there is an opening during the process of heating, unless the extreme tip only of an oxidising flame be employed.
It will be seen, on looking at the sketch of the blowpipe system, that the pair of blow-pipes farther from the observer can be caused to approach or recede at will by means of a handle working a block on a slide.
A brush flame from the larger gas tube of the single blowpipe table is most suitable for the work of bending the tubes.
The first chapter is devoted to Apparatus and Details, and the second to the General Outline of Blowpipe Analysis.
The use of a large number of burners obviates the danger of any laneing or blowpipe action, which might be present where large burners are used.
Such difficulties may be the result of a blowpipe action on the part of the burner, the over heating of the tube due to oil or scale within, or the actual erosion of the metal by particles of oil improperly atomized.
A tube of bark or hollow reed, a piece of curled up dry hide, or a gun-barrel with the nipple taken out, serves for a blowpipe to gently urge on the fire with.
A square of paper, folded diagonally across, may be used as a "feather" for a blowpipe arrow.
If you find the slightest difficulty in detaching the skin of a valuable specimen, it is far better to damage the blowpipe than to risk spoiling the skin.
Then, after softening the glass blowpipein a gas flame or the flame of a spirit lamp, it can be drawn out thin again for future work.
Supposing your blowpipe is a glass one, you can easily break off the end of it after making a cut with a very small triangular file, and the portion thus removed may be left attached to the skin.
If you have done your work neatly, the skin and blowpipe will both be quite air-tight when the clip is closed; and the air, finding no outlet, will still further inflate the skin when it expands on exposure to heat.
How to solder, either by the blowpipe or by the "bit," is now and then useful knowledge.
The silver is, however, far more quickly estimated by the blowpipe than in the wet way.
The introduction of the blowpipe into dry qualitative analysis by Axel Fredrik Cronstedt marks an important innovation.
Under the blowpipe it fuses very readily into a dark grey, and sometimes even black bead, which is slightly magnetic.
Under the blowpipe it immediately becomes white, and emits a strong animal odour, like that from fresh shells.
Part of the same grain under the blowpipe would in some instances behave like olivine, its colour being only slightly changed, and part would give a black magnetic bead.
The concretions contain a small proportion of carbonate of lime: a fragment placed under the blowpipe decrepitates, then whitens and fuses into a blebby enamel, but does not become caustic.
Some of these specimens presented a curious appearance, owing to a number of the vesicles being half filled up with a white, soft, earthy mesotypic mineral, which intumesced under the blowpipe in a remarkable manner.
An assistant gathers a small quantity of soft glass from the furnace on the end of a pointed iron rod, and causes it to adhere to the flattened surface, at a point opposite to that to which the blowpipe is attached.
The glass near the blowpipe, while hot, is touched with a cold instrument, and immediately cracks around its neck, detaching the blowpipe from the mass.
By dexterously swinging the blowpipe from side to side, which he does while standing on a plank placed over a sort of pit, and by causing it to rise on either side, he converts the pear-shape into a true cylinder, having rounded ends.
With his blowpipeready the Sakai penetrates into the forest, creeping softly among the tall grasses and bushes.
Very slowly and quietly the Sakai crouches down, lifts his blowpipe and fixing his eyes upon the black mark he has made at the end of the cane, he takes a long and steady aim.
In the same way as the aborigenes of Australia throw their boomerang with inimitable dexterity and security, the Sakai manages his blowpipe with a cleverness it is impossible to imitate or learn.
If the enamoured swain can manage his blowpipe ably enough to procure animal food for his wife their amorous desires are at once contented.
In methods of chemical analysis, both by the blowpipe and in the wet way, he effected many improvements, and he made considerable contributions to mineralogical and geological chemistry, and to crystallography.
The now cooling glass was broken from the end of the blowpipe with a sharp, snapping sound, and the blowpipe was plunged in the furnace again for another bottle.
Then they lifted the blowpipe and blew again, sharp and hard, forcing the soft glass to its proper form.
The blowpipe and the poison arrow are most dangerous.
It was none of the old-time gambling places, like Danfield's, with its steel door which Craig had once cut through with an oxyacetylene blowpipe in order to rescue a young spendthrift from himself.
He might have used thermit or an oxyacetylene blowpipe for all I would care.
But there is no hole," objected Kennedy, "not a trace of the use of thermit to burn the way in or of the oxyacetylene blowpipe to cut a piece out.
