IMPROVEMENTS IN MINING APPLIANCES.

Dunstan Times, Issue 470, 21 April 1871, Page 3

IMPROVEMENTS IN MINING APPLIANCES.

(San Francisco Weelchj Bui lei 'a.)

The report upon our placer mines just made bv Mr. W. A Skidmore to the U.S Mining shows a most encwinging condition. The last year has fken signalized by the introduction intoxGa'ifornia mining of improvements wtiich must give new life to the business, and add mi'lions to our annual yield of go'd. Chief among these are the hydrau'ic nozzles, which, while reducing the expenses, more than doub'e the working power of the hydraulic claims. Of these there are three now in use—Craig’s “Monitor,” Fisher's “Knuckle Joint” and Haskin’s “Improved Nozz'e,”all three, though by different devices, accomplishing end—that of dispensing entirely -trith the use of hose by the attaching of a moveab’e and easily managed nozzle directly to the iron water pipe, thus making it possible to direct against a bank a stream of as great volume and pressure as iron pines can be made to carry without bursting.

It may not he amiss t" some our leaders to exphain that hydraulic wash-ing-mow now the most extensive branch of go’d mining in California—is conducted bv directing against a hill-side powerful streams of water, which cut into and undermine the bank, the water as it xuins off carrying with it the disengaged dirt and gravel

through 'ong flumes (sometimes over a mile in length), where riffles charged with quicksilver arrest the gold as it is separated. When hydraulic mining first commenced, canvas hose was used to convey the water from the ditches into the claims and to the points where it was to be hur ed by the force of the fill against the banks. Tlunigh made In the most cai ehil of the strongest sail c'd% such hose could | not bear the pressure of a fall or head of more than eighty or one hundred feet, and, moreover, rotted rapidV, and was constancy giving way. The rapid wearing of the canvas hos°, as well as the necessity of using large-, streams and greater force to move the firm’y compacted dirt and grave', fina'ly led, in all large claims, to the substitution of sheet-iron pipe, to bring the water from the supp’y ditches into the c'aims. Thus a gi eat increase of the volume and force of the water carried was made possible ; but the increase in tbe power and volume of the streams used was still limited by the ability to direct them by hand, and the necessity of having a flexible discharge-piece connecting the pipe with the nozzle, and permitting the latter to moved as occasion required. However, by making the dischargepiece of stout canvas covered with a network of matting of strong rope, the size and power of the streams used, and consequently t|ieir efl'c'ency, was largely increased. Biltstill the desid eratum of an easily \mnnged stream as powerful as iWn pi ties could carry was not secured until the Study of die problem by our miners gave birth to the inventions we have a'luded to, and which are a'ready almost i" general use. These new hydrau ic nozzles are attached directly to the iron pipe, and by a simple but ingenious contrivance (which differs somewhat in each invention) are given both a lateral and perpendicular motion, which can ea.d'y be directed by one man. Instead of two hundred a d fifty inches of water with a head of from one hundred and fifty feet, twelve hundred inches of water, with a head of three hundred feet, can now he driven against a bank in a single stream. The saving thus effected is enormous. It is not on'y that the water formerly sent through seven or eight ordinary hose pipes, each requiring from one to three men, can now be managed by a sing'e hand; but its efficiency is greatly increased. The disintegrating power of water forced upon a bank in one stream is at least double that of the same amount th'own in two separate streams. C oi-ely compacted gravel and hard cement, which water, as formerly used could not move, and which required the pick or the blast, are easily disintegrated and washed away by the tremendous force of the gigantic streams now used. Those inventions, too, save human life as well labor. Formerly, the had to stand bo close to the they were frequently cnishoSr by the toppling over or caving of Immense masses of earth. But the powerful streams now coming into use they can remain at a

safe distance and yet do more execu tion than before.

Improvements have likewise been made in the means of cutting through rock, as important in hydraulic, as in quartz mining, for in near y all the hydraulic claims ; ong tunnels have to be cut to furnish out ets. The introduction of giant powder, against which the Grass Yalley miners so foolish'y ond so vainly struck, by reducing the amount of dril ing required, and permitting the substitution of single-handed for two-handed drills reduced the expenses of tunnelling from thirty three to twenty per cent. And now comes an invention which will make a further Mjbrmous saving both in expense„msd in time This is the diamond-poitttefflmower drill, which bores through vi/fik arbost as quickly as a carpenter with brace and bit bores through a plank. At Telegraph Hill, it bored twenty-feet holes in three hours, which drilled by hand required the lab - r of six men from twenty to twenty five days, and has been tried in various parts of the state with like results, showing itsed' capab'e ot going through even the white crystal quartz, the hardest rock in California, at the rate of llireo feet per hour. In the long 2270 feet tunnel of the Blue Point Ffydr ulic Company now being cut at Smartsvide, where the rock is so hard that a gang of six men have worked for a month without making ten feet, the diamond drib has shown itself capab e of boring at the rate of an inch a minute. One of these machines is being made at th ■ Fu’ton Foundry for use in this tunnel. It will be run by compressed air, it being impossible to use steam in loag tunnels on account of the heat, the escaping air performing a'so the task of ventilation. In this machine, the dri s will be carried on a truck, which one man can run up to the face of the tunnel or back again in a moment, and will be so arranged that the holes can bo bored in any place or any ang'e required. The cost of the entire machine will be 10,000 do’s., a sum which is insignificant compared with the cost of cutting these long tunnels by hand Besides its use for 'blasting purposes, the diamond drill must prove of incalcu'n.able value for prospecting, as it can be driven in a distance of from six to seven hundred feet, taking out a cove of the rock as it goes along, thus in many cases saving expensive shafts and drifts.

Goldsmith’s Work. The process ot fine-art manufacture in this branch of trade is strikingly exemplified in a little work published by Mr. J. W. Benson, of No. 25, Old Bond-street, and of the City Steam Factory, 58 and GO, Lndgate-hill, London. It is enriched and embellis lied with designs, by Italian, French, and English artistes, of brooches, bracelets, ear-rings, and other articles, suitable for personal wear, or for wedding, birth-day, or other presents, with their prices. Mr. Benson, who liohls the appointment to H.E.R. the Prince of Wales, has also published a very interesting pamphlet on the Piise and Progress of Watohmak.iug. Those pamphlets stamps each, anibtjieycahnotbetoo strongly recommenced to those conSEiiiplating a purchase, especially to the country or abroad, who are thus enabled to select any article they may require, %nd have it forwarded in perfect safety.