Volume 28 (1874) (430 pages)

June 20, 1874.1, MINING AND SCIENTIFIC PRESS. Improved Method of Observing Altitudes of the Sun at Sea. The science and art of navigstion stand among the proudast achtevements of modern thought and researcb. The accurate determination of tha plscos of the fixed atars, and of tha motion and position of the members of the solar system, gave the navigator nomerous well determined points for observation. But the attsinmsnt of a corresponding perfection in fashioning instruments has ever bsffled hnmsn skill, and sver will. For althongh we are entitled to look for wonders, at the hands of the artist, wa cannot expect miracles! And we hence see that the demands of the astronomer, and even the nautical astronomer or navigator, will always surpass the power of the instrnment maker. ‘They must therefore so combine their observations, so familiarize themselves with all the oauses which may produce instrnmental derangement, and with all the peculiaritiea of structnre and material of each instrument used, as not to allow themselves to be misled hy its errors, but to extract from their indications all that is trne and reject all thst is erroneons. Itis true that the astronomercan so weigh hia observations in the balance of the method of leaat squares, and so thoroughly sift them by Peirce’a criterion, that hardly the trace of a large error remains; and the more minnte errors being casual and accidental, sometimes lie one way, sometimes the other; sometimes diminishing and sometimes tending to increase the resnits. And, inasmuch as the theory of probabilities tells us that these accidental errors are as liable to lie one way as the other, we hence have but to greatly multiply onr ob. servations under varied circumatances and take the mean or average of the results obtained and we have this class of errors so far snbdued, by thns aetting them to destroying one another, thatthey no longer sensibly vitiate our practical results, This principle of repetition, thongh so simple in theory and so heautiinl in practice, when the instrument and observer are upon a firm basis, utterly faila of application where the obaerver and his instrnment aro tossed alike on the ooean’s wave, and the object observed is "on wing.” It. becomes therefore imperative upon the navigator, if he wonld trace accurately his ship’s path over the traokless ocean, that he attain rigorous correctness in tha resnits of “teach” of his instrnmental measurements; and to this end his constsnt care and vigilance must be directed to the detection and compeuaation of errors, either by annihilating or taking account of and allowing for them. This latter method of taking account of and allowiug for errors, is that ordinarily pnrsued by the navigator; but it has navigated so many noble ships to the bettom of the sea, that the voice of humanity and the interests of commerce alike demand such a modificstion of the methods of observation, and the forms of the instruments, as to annihilate effectually and alike errors inherent in the observer, in the instrument and in the atmosphere. In the method of taking observations uow generally practiced by the navigator, instrumental adjustmeuts, atmospheric refraction and the impressibility of the optic nerve are all depended upon as constant and invariable during the observations; while, in fsct, they all are ever fluctuating. The ever-varying fluctuations of heat and cold are continually changing the amount of atmospheric refraction. as also that of every instrumental adjnstment. And it is a well known fact in optics that the irradiation (which causes bright objects to appear larger than they really are) varies with the length of time during which we lock npon the object, during the first few moments of observation gradnally decreasing; and then, as the optic nerve becomes fatigued, the optical illnsion (irradiation) reappears magnified ten-fold.: These are not mere speonlative sources of errors, bnt practical annoyances whioh every observer has to contend with—the inoompetent navigator, of course, slurring them over as refinements too delicate to deal with, while he attributes the error thus introduced into his position, to the action of imaginary ocean currents; but the thorough navigator meets these errors fuirly, aud sets about annihilating them. Yet it may be interesting to those navigators who insist on neglecting these finer instrumental errors, to know that very many of the sextants used in navigating vessels have an excentricity ranging from one to fonr minutes, which is often aggravated by parallax of,index-glass; and his positions are vitiated to the fnll extent of these neglected errore. By the ordinary method of ubserving enccessive contacts of the opposing limbs of the sun with the horizon, eveuif the mind from one observation to the other retains fresh and full the vision of the contact, still the observer will fail to make the contact of the horizon with the perimeter of the sun at eqnal distances from its center, becanse he makes these contacte at different instants of time, when the eye is differently affected by irradiation and fatigue, And hence, what would appear one moment a delicate contact would one minute afterward be wide of the mark. And thus itis, in the observations thns made with an instrument that is varying, with a vision that is varying and throngh an atmosphere that is varying, we can clearly see the source of the errors which have lured many an unsuspecting ship fatally onward against rocks and reefs. But by the method of observing proposed by Mr. T. J. Lowry, of the U.S. Coast Survey, and described by him at a recent meeting of the California Academy of Sciences, and with the form of instrument herein designated, we avoid in part, and in the remainder essentially annihilute those most fruitfnl sources of errors. By pleasing within the instrument itself the means ° . Self-CorrectionWe have tho most effectual cheoks upon its errors of constrnction and the changes of its/. F; adjnstments, Thus, from very simple geometrical considerations it msy be easily shown that the errors of eccentricityand of graduation are totally eliminated by the mean of the readiuga of two verniers 180 deg. apart, and by measnring the angles on different parts of the arc;‘and by using an index-glass susceptible of reversal between the parts of a set of observations we hanishevery trace of error from parallax of iudex-glass from our results. And every error of observation — snch as arise, for example, from inexpertness, defective vision, slowness in sezing the exact instant of oconrrence of a phenomonen, and from atmospherie iudistinotness, and insnfficient optical ‘power in the instrnment—are.all alike essentially checked by observing the contacts of the two opposiug limbs of the sun with the horizon at the same instant. Now, since we have the contacts of the upper and lower limbs of the sun in the field of view at the same moment, we have before our eyes a most thorough check on the cbaracter of the contacts, since by direct and instantaneous optical comparison we make each of them eqnally well. IMPROVED ‘ “te And, moreover, since we make the contacts of both limbs of the sun with the horizon at the’ same instant, we have in “ each sight,”’ an altitude, complete in itself, without the aid of'a snpposition of ‘the constsncy of atmospheric refraction, or the stability of instrnmental adjustments, or the conetancy of the impressibility of the optic nerve, or the aid of memory. But, a8 we cannot measure what we cannot. see, it is obvidus that by the ordinary method of snecessive single contacts those errors, tdo minute for low optical power, enter and vitiate the results [to their full extent. But by Mr. Lowry’s method of double contacts at the same instant, we detect and avoid these errors which would otherwise elude onr vision. As for example, snppose we make what appears to be a contact of the upper limb of the snn with the horizon, and then by glancing at the other contact, of the lower limb and the horizon, in the same field of view, it will appear a contact equally nice as the other, if the first contact was exact, butif it was at all in error, then the second will be in error twice as much ae the first; and thus it is, by doubling these errors, which the eye cannot discern nor the touch perceive, are we enabled to sift them from our cbservations. Still the observer shonld use ths most powerfnl telescope available. The improvement now proposed by Mr. Lowry, (besides a few other matters of detail), inthe ordinary reflecting angular instrnments, is a device for duplicating the amage of an object by optical means. This he accomplishes by fixing an extra index-glass directly above, or in the same plane with that of the ordinary one of the reflecting repeating cirele, and at an angle therewith, eqnal to the apparent semi-diameter of the san; or, perhaps, a more complete solution of the problem, is to fix a small sphere of Iceland spar on' the direct line between the index and horizon glasses, (see Fig. No. 1,) and thus obtain two images of the snn equally “distinct, (sees s°, Fig. No. 4.) This sphere to be monnted in a light metallic frame, so connected with a micrometer that its most delicate movements can be read off. In Fig. No. 2, ais the snn, and }, its duplicated image, as seen in the hofizon glass; ‘and 6 is this same dbplicated image brought in contact with the horizon; ¢ is the position of the . , observer. Now, in observing, it makes buat little difference whether these duplicated images are exactly tangent, slightly overlapning, or slightly separated, (as shown atd, f, and ¢, in ‘ig. No. 4); for in the first case we have but to bring the horizon to the point of taugency; in the second, ta Lisect the two exterior angles; or in the third, to bisect the space between the adjacent limbs of the sun. It is obvious that this method of observing the contacts of both limbs of the sun at the same instant is equally well adapted for double altitudes; the appearance of the images then is shown at m, in Fig. No. 4. Other improyemeuts devised by Mr. Lowry are:.lst. A reversible double reflecting index glass, (see Fig. No. 3,) which eliminates the error due to its parallax; and the 2d is making both faces of index glass reflectors, and fixing a glass prism, with silvered hypothenuse, on the line of sight behind the index glass and at snch an angle as to reflect the rays first reflected from the back face of index glass parsllel to the line of aight. This device enables us to measure any angle, (shown in Fig. No. 1.) Itis obvious that any two angle reflecting instrumeut may also be made to give this dnplication of images; and also give an altitnde and its supplement at the same instant, and thns give nsithe algebraic snm of the existing refraction and dip. These improvements are all INSTRUMENT FOR OBSERVING SOLAR ALTITUDES equally adapted and easily applied to any reflecting angular instrument, “ By making these attachments to'the French reflecting, repeating circle (ses Fig. No. 1) we have an instrument capable of not only eliminating its own errors, but those of observation,’ ad well as those due'to sudden atmospheric changes, and we have an instrument theoretically almost perfect. Through the efforts of Laplace, Newton‘and Peirce’ the theory of nautical astronomy hss reached a point of perfection that only awaits the determination of the true dimensions of the solar system (which it is hoped the next transit of Venus will give) to make it all that can be desired. ‘The invention of the chronometer has practically solved the problem of longitudes. And the needle of the mariner's compass has felt the touch of a Ritchie and trembles no more. Whilst Beecher and Davidson have given the navigator artificial horizons that leave but little to be desired in that direction.” But still improved méthods of observation are wanted to decrease the frightful number of marine disasters, And though the ideas here advanced are believed to be a step in the right direction, yet they are also thrown out with a hope of eliciting from others a more complete solution of this problem, than which nene other niore interests mankind. And the complete solution of it—that would make practical navigation one of the exact arts—wonld evoke the lasting gratitude of civilized man the world over. Graven claims iu the vicinity of Silver City are yielding liberally. Matthewe & Co., who ere working a claim in Nigger Gnlch, a short: distance weet of the town, are making from $15 to $20 per day to the man. Sr. Heuena, Napa county, sent awsy 31,329 pounds of quicksilver during the first five months of this year, ' 4 Working .Claims by Tunnels. Willls Drummond; Commissioner of the, hand! Office, decided, Aug. 27th, 1872, that work done and expenditures made iu constrncting a funuel, intended for the development and improvement of lodes, would not satisfy the legal reqnirements of the Act of May 10th, 1872, a3 to. expenditure on claims ; bnt that snoh expenditure or laoor must, be made in good faith unon each lode clainied; other wise the same would he subject to re-looation by other parties, as provided by law. The case which brought forth this decision was that of the Helmick Silver Mining Company, who were the claimants of nine separate lodes, all of which it was their purpose to develop and improve by a mining tnnnel. Thie decision of the Commissioner was approved by W. H. Smith, Acting Secretary of the Interior. In consequence of this decision, a bill was introduced in Congress, which chsnged this law and amended it so as to read; ‘‘That the fifth section of the Act be and the same is hereby amended so that when aperson of company shall rnn a tunnel for the purpose of develbping a lode or lodes, owned by said person or’ company, the money so expended in said tun» nel shall be taken and considered as expended: on said lode or lodes, whether located prior tb or since the passage of said Act; and such person or company shall not be reqnired to perform work on the surface of said lode or lodes, in order to hold the same, as reqnired by said’ Act.’’ As far we have learned, the bill has not yet been zcted npon, although it is a jnst and. necessary one. However, it does not matter much, as W. W. Curtis, Acting Commissioner, has changed the ruling of Commissioner Drummond, as the following note to Senator Sargent will show: GENERAL Lanp OFFIoz, WasHineroy, D, €., May 29, 1874.—Hon. A. A. Sergent—Sir: Referring to yourrecent personal cell, I heve to state that where a tunnel is run for the development of « particular vein or lode, it is held by this officeto be work upon thatvein or lode within the meaning of mining Acte of Oongrere; The required expendituree may he made either from the:eurface of a mining cleim or ina tunnel run for the development of such mine. Very respectfully, etc., W. W. Cunrie. Aoting Commissioner . This is as it should be—only if it had been so. decided befere, it wonld have saved many nvm. ers considerable money. Tue Parace Hoteu.—The new hotel now be-ing erected on Market street, opposite the Graudi Hotel, will cover an area of 96,250 square feet. The frontage on New Montgomery street willi be 350 feet; on Market, 275 feet; on Annie, 350 feet, and on Jessie, 275 feet. It will be seen by this that our new hotel covers an area of sround nearly three times that of tbe New York ‘Windsor Hotel,” which covers 36,000 square feet, and more than three timesthat of Leland's “Sturtevant House,” which rests npon 30,000 squure feet. About 4,000,000 bricks have been ‘ased already; when finisbed there will be 16,000,000 bricke in it; 16,000 barrels of lime and cement; and 600 tons ut iron. There are now 300 men at work on the bnilding, and 200 carpenters will be put at work when the strnctnre is ready for them. There will be 30 miles of gas, steam and water pipe. The building will be six stories high and cost $1,000,000. Transit or Venvs.—Professor George Davidson, of the U.S. Coast Survey, and President of the California Academy of Sciences, will said for Japan about the 15th of Angust or Ist of . September, to take observations of the transit of Venus. O.H.Tittman, of the Coast Survey, who will be his chief assistant, is expected to arrive in San Francisco shortly with the outfit. Three photographers will accompany the party, all of whom are now practising with Dr. Dresbs: and Professor Newcomb in Washington. The Professor has not decided on the @xsct point of observation, but intends. to make his selection when he arrives in Japan. Prernc Commencep.—Last week piping was: commenced in the Emerson hydraulic claim in Happy Valley, Calaveras connty. A new flume 720 feet in length, two feet wide, with a grade of six inches to the box, has been laid. The hydrauliz has a pressnre of 140 feet, the water— 250 inches—being conveyed to the mine in a 18-inch iron pipe. The claim is several inches in area, the gravel varying from 60 to 100 feet in depth. ’ Tur Brother Jonathan quicksilver mine, recently discovered by a party sent out by Dr. C. E. Davis, of St. Helena, consisting of T. Walker, W. C. Davis and B. E. Hunt, is now being worked. A company has been formed of the fonr above named gentlemen, a tunuel is being run, and the ore is said to be very promising. Brus of lading were received Monday by the Directors of the San Francisco Smelting Works for 345 tons of ore from Salt Lake, which will probably reach here Thursday or Friday. Op: erations will probably commence at the works the first part of next week. Eserparnt & Avgora.—It is rnmored that a body of $70 ore has been found under the old Peerless chsmber in the Mberhardt & Aurora mine, White Pine. The mine is turning out 40 tons per day. 2 Rica discoveries of silver are reported about 10 miles north of Wells, Nev. The vein is large and the ore assays almost $400 per ton. Reox riffles are coming in vogue with miners { iu Montana, and are well liked.

June 20, 1874.1, MINING AND SCIENTIFIC PRESS. Improved Method of Observing Altitudes of the Sun at Sea. The science and art of navigstion stand among the proudast achtevements of modern thought and researcb. The accurate determination of tha plscos of the fixed atars, and of tha motion and position of the members of the solar system, gave the navigator nomerous well determined points for observation. But the attsinmsnt of a corresponding perfection in fashioning instruments has ever bsffled hnmsn skill, and sver will. For althongh we are entitled to look for wonders, at the hands of the artist, wa cannot expect miracles! And we hence see that the demands of the astronomer, and even the nautical astronomer or navigator, will always surpass the power of the instrnment maker. ‘They must therefore so combine their observations, so familiarize themselves with all the oauses which may produce instrnmental derangement, and with all the peculiaritiea of structnre and material of each instrument used, as not to allow themselves to be misled hy its errors, but to extract from their indications all that is trne and reject all thst is erroneons. Itis true that the astronomercan so weigh hia observations in the balance of the method of leaat squares, and so thoroughly sift them by Peirce’a criterion, that hardly the trace of a large error remains; and the more minnte errors being casual and accidental, sometimes lie one way, sometimes the other; sometimes diminishing and sometimes tending to increase the resnits. And, inasmuch as the theory of probabilities tells us that these accidental errors are as liable to lie one way as the other, we hence have but to greatly multiply onr ob. servations under varied circumatances and take the mean or average of the results obtained and we have this class of errors so far snbdued, by thns aetting them to destroying one another, thatthey no longer sensibly vitiate our practical results, This principle of repetition, thongh so simple in theory and so heautiinl in practice, when the instrument and observer are upon a firm basis, utterly faila of application where the obaerver and his instrnment aro tossed alike on the ooean’s wave, and the object observed is "on wing.” It. becomes therefore imperative upon the navigator, if he wonld trace accurately his ship’s path over the traokless ocean, that he attain rigorous correctness in tha resnits of “teach” of his instrnmental measurements; and to this end his constsnt care and vigilance must be directed to the detection and compeuaation of errors, either by annihilating or taking account of and allowing for them. This latter method of taking account of and allowiug for errors, is that ordinarily pnrsued by the navigator; but it has navigated so many noble ships to the bettom of the sea, that the voice of humanity and the interests of commerce alike demand such a modificstion of the methods of observation, and the forms of the instruments, as to annihilate effectually and alike errors inherent in the observer, in the instrument and in the atmosphere. In the method of taking observations uow generally practiced by the navigator, instrumental adjustmeuts, atmospheric refraction and the impressibility of the optic nerve are all depended upon as constant and invariable during the observations; while, in fsct, they all are ever fluctuating. The ever-varying fluctuations of heat and cold are continually changing the amount of atmospheric refraction. as also that of every instrumental adjnstment. And it is a well known fact in optics that the irradiation (which causes bright objects to appear larger than they really are) varies with the length of time during which we lock npon the object, during the first few moments of observation gradnally decreasing; and then, as the optic nerve becomes fatigued, the optical illnsion (irradiation) reappears magnified ten-fold.: These are not mere speonlative sources of errors, bnt practical annoyances whioh every observer has to contend with—the inoompetent navigator, of course, slurring them over as refinements too delicate to deal with, while he attributes the error thus introduced into his position, to the action of imaginary ocean currents; but the thorough navigator meets these errors fuirly, aud sets about annihilating them. Yet it may be interesting to those navigators who insist on neglecting these finer instrumental errors, to know that very many of the sextants used in navigating vessels have an excentricity ranging from one to fonr minutes, which is often aggravated by parallax of,index-glass; and his positions are vitiated to the fnll extent of these neglected errore. By the ordinary method of ubserving enccessive contacts of the opposing limbs of the sun with the horizon, eveuif the mind from one observation to the other retains fresh and full the vision of the contact, still the observer will fail to make the contact of the horizon with the perimeter of the sun at eqnal distances from its center, becanse he makes these contacte at different instants of time, when the eye is differently affected by irradiation and fatigue, And hence, what would appear one moment a delicate contact would one minute afterward be wide of the mark. And thus itis, in the observations thns made with an instrument that is varying, with a vision that is varying and throngh an atmosphere that is varying, we can clearly see the source of the errors which have lured many an unsuspecting ship fatally onward against rocks and reefs. But by the method of observing proposed by Mr. T. J. Lowry, of the U.S. Coast Survey, and described by him at a recent meeting of the California Academy of Sciences, and with the form of instrument herein designated, we avoid in part, and in the remainder essentially annihilute those most fruitfnl sources of errors. By pleasing within the instrument itself the means ° . Self-CorrectionWe have tho most effectual cheoks upon its errors of constrnction and the changes of its/. F; adjnstments, Thus, from very simple geometrical considerations it msy be easily shown that the errors of eccentricityand of graduation are totally eliminated by the mean of the readiuga of two verniers 180 deg. apart, and by measnring the angles on different parts of the arc;‘and by using an index-glass susceptible of reversal between the parts of a set of observations we hanishevery trace of error from parallax of iudex-glass from our results. And every error of observation — snch as arise, for example, from inexpertness, defective vision, slowness in sezing the exact instant of oconrrence of a phenomonen, and from atmospherie iudistinotness, and insnfficient optical ‘power in the instrnment—are.all alike essentially checked by observing the contacts of the two opposiug limbs of the sun with the horizon at the same instant. Now, since we have the contacts of the upper and lower limbs of the sun in the field of view at the same moment, we have before our eyes a most thorough check on the cbaracter of the contacts, since by direct and instantaneous optical comparison we make each of them eqnally well. IMPROVED ‘ “te And, moreover, since we make the contacts of both limbs of the sun with the horizon at the’ same instant, we have in “ each sight,”’ an altitude, complete in itself, without the aid of'a snpposition of ‘the constsncy of atmospheric refraction, or the stability of instrnmental adjustments, or the conetancy of the impressibility of the optic nerve, or the aid of memory. But, a8 we cannot measure what we cannot. see, it is obvidus that by the ordinary method of snecessive single contacts those errors, tdo minute for low optical power, enter and vitiate the results [to their full extent. But by Mr. Lowry’s method of double contacts at the same instant, we detect and avoid these errors which would otherwise elude onr vision. As for example, snppose we make what appears to be a contact of the upper limb of the snn with the horizon, and then by glancing at the other contact, of the lower limb and the horizon, in the same field of view, it will appear a contact equally nice as the other, if the first contact was exact, butif it was at all in error, then the second will be in error twice as much ae the first; and thus it is, by doubling these errors, which the eye cannot discern nor the touch perceive, are we enabled to sift them from our cbservations. Still the observer shonld use ths most powerfnl telescope available. The improvement now proposed by Mr. Lowry, (besides a few other matters of detail), inthe ordinary reflecting angular instrnments, is a device for duplicating the amage of an object by optical means. This he accomplishes by fixing an extra index-glass directly above, or in the same plane with that of the ordinary one of the reflecting repeating cirele, and at an angle therewith, eqnal to the apparent semi-diameter of the san; or, perhaps, a more complete solution of the problem, is to fix a small sphere of Iceland spar on' the direct line between the index and horizon glasses, (see Fig. No. 1,) and thus obtain two images of the snn equally “distinct, (sees s°, Fig. No. 4.) This sphere to be monnted in a light metallic frame, so connected with a micrometer that its most delicate movements can be read off. In Fig. No. 2, ais the snn, and }, its duplicated

image, as seen in the hofizon glass; ‘and 6 is this same dbplicated image brought in contact with the horizon; ¢ is the position of the . , observer. Now, in observing, it makes buat little difference whether these duplicated images are exactly tangent, slightly overlapning, or slightly separated, (as shown atd, f, and ¢, in ‘ig. No. 4); for in the first case we have but to bring the horizon to the point of taugency; in the second, ta Lisect the two exterior angles; or in the third, to bisect the space between the adjacent limbs of the sun. It is obvious that this method of observing the contacts of both limbs of the sun at the same instant is equally well adapted for double altitudes; the appearance of the images then is shown at m, in Fig. No. 4. Other improyemeuts devised by Mr. Lowry are:.lst. A reversible double reflecting index glass, (see Fig. No. 3,) which eliminates the error due to its parallax; and the 2d is making both faces of index glass reflectors, and fixing a glass prism, with silvered hypothenuse, on the line of sight behind the index glass and at snch an angle as to reflect the rays first reflected from the back face of index glass parsllel to the line of aight. This device enables us to measure any angle, (shown in Fig. No. 1.) Itis obvious that any two angle reflecting instrumeut may also be made to give this dnplication of images; and also give an altitnde and its supplement at the same instant, and thns give nsithe algebraic snm of the existing refraction and dip. These improvements are all INSTRUMENT FOR OBSERVING SOLAR ALTITUDES equally adapted and easily applied to any reflecting angular instrument, “ By making these attachments to'the French reflecting, repeating circle (ses Fig. No. 1) we have an instrument capable of not only eliminating its own errors, but those of observation,’ ad well as those due'to sudden atmospheric changes, and we have an instrument theoretically almost perfect. Through the efforts of Laplace, Newton‘and Peirce’ the theory of nautical astronomy hss reached a point of perfection that only awaits the determination of the true dimensions of the solar system (which it is hoped the next transit of Venus will give) to make it all that can be desired. ‘The invention of the chronometer has practically solved the problem of longitudes. And the needle of the mariner's compass has felt the touch of a Ritchie and trembles no more. Whilst Beecher and Davidson have given the navigator artificial horizons that leave but little to be desired in that direction.” But still improved méthods of observation are wanted to decrease the frightful number of marine disasters, And though the ideas here advanced are believed to be a step in the right direction, yet they are also thrown out with a hope of eliciting from others a more complete solution of this problem, than which nene other niore interests mankind. And the complete solution of it—that would make practical navigation one of the exact arts—wonld evoke the lasting gratitude of civilized man the world over. Graven claims iu the vicinity of Silver City are yielding liberally. Matthewe & Co., who ere working a claim in Nigger Gnlch, a short: distance weet of the town, are making from $15 to $20 per day to the man. Sr. Heuena, Napa county, sent awsy 31,329 pounds of quicksilver during the first five months of this year, ' 4 Working .Claims by Tunnels. Willls Drummond; Commissioner of the, hand! Office, decided, Aug. 27th, 1872, that work done and expenditures made iu constrncting a funuel, intended for the development and improvement of lodes, would not satisfy the legal reqnirements of the Act of May 10th, 1872, a3 to. expenditure on claims ; bnt that snoh expenditure or laoor must, be made in good faith unon each lode clainied; other wise the same would he subject to re-looation by other parties, as provided by law. The case which brought forth this decision was that of the Helmick Silver Mining Company, who were the claimants of nine separate lodes, all of which it was their purpose to develop and improve by a mining tnnnel. Thie decision of the Commissioner was approved by W. H. Smith, Acting Secretary of the Interior. In consequence of this decision, a bill was introduced in Congress, which chsnged this law and amended it so as to read; ‘‘That the fifth section of the Act be and the same is hereby amended so that when aperson of company shall rnn a tunnel for the purpose of develbping a lode or lodes, owned by said person or’ company, the money so expended in said tun» nel shall be taken and considered as expended: on said lode or lodes, whether located prior tb or since the passage of said Act; and such person or company shall not be reqnired to perform work on the surface of said lode or lodes, in order to hold the same, as reqnired by said’ Act.’’ As far we have learned, the bill has not yet been zcted npon, although it is a jnst and. necessary one. However, it does not matter much, as W. W. Curtis, Acting Commissioner, has changed the ruling of Commissioner Drummond, as the following note to Senator Sargent will show: GENERAL Lanp OFFIoz, WasHineroy, D, €., May 29, 1874.—Hon. A. A. Sergent—Sir: Referring to yourrecent personal cell, I heve to state that where a tunnel is run for the development of « particular vein or lode, it is held by this officeto be work upon thatvein or lode within the meaning of mining Acte of Oongrere; The required expendituree may he made either from the:eurface of a mining cleim or ina tunnel run for the development of such mine. Very respectfully, etc., W. W. Cunrie. Aoting Commissioner . This is as it should be—only if it had been so. decided befere, it wonld have saved many nvm. ers considerable money. Tue Parace Hoteu.—The new hotel now be-ing erected on Market street, opposite the Graudi Hotel, will cover an area of 96,250 square feet. The frontage on New Montgomery street willi be 350 feet; on Market, 275 feet; on Annie, 350 feet, and on Jessie, 275 feet. It will be seen by this that our new hotel covers an area of sround nearly three times that of tbe New York ‘Windsor Hotel,” which covers 36,000 square feet, and more than three timesthat of Leland's “Sturtevant House,” which rests npon 30,000 squure feet. About 4,000,000 bricks have been ‘ased already; when finisbed there will be 16,000,000 bricke in it; 16,000 barrels of lime and cement; and 600 tons ut iron. There are now 300 men at work on the bnilding, and 200 carpenters will be put at work when the strnctnre is ready for them. There will be 30 miles of gas, steam and water pipe. The building will be six stories high and cost $1,000,000. Transit or Venvs.—Professor George Davidson, of the U.S. Coast Survey, and President of the California Academy of Sciences, will said for Japan about the 15th of Angust or Ist of . September, to take observations of the transit of Venus. O.H.Tittman, of the Coast Survey, who will be his chief assistant, is expected to arrive in San Francisco shortly with the outfit. Three photographers will accompany the party, all of whom are now practising with Dr. Dresbs: and Professor Newcomb in Washington. The Professor has not decided on the @xsct point of observation, but intends. to make his selection when he arrives in Japan. Prernc Commencep.—Last week piping was: commenced in the Emerson hydraulic claim in Happy Valley, Calaveras connty. A new flume 720 feet in length, two feet wide, with a grade of six inches to the box, has been laid. The hydrauliz has a pressnre of 140 feet, the water— 250 inches—being conveyed to the mine in a 18-inch iron pipe. The claim is several inches in area, the gravel varying from 60 to 100 feet in depth. ’ Tur Brother Jonathan quicksilver mine, recently discovered by a party sent out by Dr. C. E. Davis, of St. Helena, consisting of T. Walker, W. C. Davis and B. E. Hunt, is now being worked. A company has been formed of the fonr above named gentlemen, a tunuel is being run, and the ore is said to be very promising. Brus of lading were received Monday by the Directors of the San Francisco Smelting Works for 345 tons of ore from Salt Lake, which will probably reach here Thursday or Friday. Op: erations will probably commence at the works the first part of next week. Eserparnt & Avgora.—It is rnmored that a body of $70 ore has been found under the old Peerless chsmber in the Mberhardt & Aurora mine, White Pine. The mine is turning out 40 tons per day. 2 Rica discoveries of silver are reported about 10 miles north of Wells, Nev. The vein is large and the ore assays almost $400 per ton. Reox riffles are coming in vogue with miners { iu Montana, and are well liked.