Arizona weekly journal-miner., 1899-02-01
A SERIOUS PROBLEM.
THE COMPASS AND THE GROWING
 USE OF ELECTRICITY

A Danger TAAf the Magnetic Needle
 May Be Rendered Practically Use-
 less to the Mariner and the Sur ] Seyor-A Curious Discovery.
 Although the invention and introduc-
 tion of the trolley system of street mil ! ways have been of inesiimable value to
 civilization it has incidentally wrought
 some harm here and there. Emphasis
 was laid on one of these drawbacks to i electric traction in the address delivered 1 by Professor A. W Fucker at a recent
 meeting of the British Association For ! the Advancement of Science.
 l In various parts of the world observa- ! tories have been established for the pur | pose of keeping track of the changes in | the direction in which the magnetic
 needle points It was long ago discov-
 cred not only that the compass does not ] aim directly at the north pole, but that | the amount Of variation in its indica- ! tiOns from true north undergoes slow | alterations Hence 1t is necessary Co mako fresh charts. showing the va-ia- | tion for different parts of the globe | every few years. But in order to get ! the data for such cOrrections-of the 1 highest importance Co the surveyor and
 mariner-ii Is requisite that careful ob- servati0ns be made continuously at Q
 number of widely separated points Two of the most famous and hitherto | useful institutions of this class are situ- | ated in Washington, in the grounds of | the naval observatory and in Toronto ! The interference Of the electric currents | that run through the earth and the ! track of trolley lines which have been ! constructed near these ohservatories in | terfere so much with the behavior of i, the instruments of both places that the 1 records now obtained are prsctica y | worthless And the experts are greatly
 puzzied by tbe problem of escaping from | this vexa:ious interruption of their ! work
 So delicate are the influences which ! the magnets in such an observatory are | intended 10 inyestisate that they can be | perceived oniy when the apparatus is most scrppulOusly guarded. The room ' in which they are mounted is under | ground Visitors are never admitted ex-
 cept under unusual circumstances and are rCgu!red Go deposit their jlckknives f keys and all other metallic objects about 1 their persuns before entering the apart ! meDt The magnets. generally bars of | steel not over SIX inches long. are poised | sb0yo Q scaie that Is graduated Co the | most minute fractions and a telescope, i on an adjacent pillar. is used to read ! the fluctuations. which are too small to i be discernible by the unassisted eye. A l tiny mirror, as big as dime, catches a beam of light more slender than the lead in a pencil and reflects it away Co
 sheet of slowly moving photographic paper, on which a permanent record is made. The arrangement of the apparatus
 is such that the movement of the mag
 net is magrihed many times in the rec
 ord, in order to render the changes peI-
 ceptible
 There arc three sets of instruments
 on duty in such an observatory One
 swings horizontally, like a mariners
 compass. Another dips up and down.
 A third is designed to measure the in-
 tensity of the earth's magnetism, which
 is a separate thing from the direction
 in which 1t acts And 90 sensitive are
 they that their readings are apt to be
 interfered with by exceedingly trivial
 causes IL Is customary for the superin-
 tendent to inscribe on the scroll Visit
 ors admitted " whenever such a breach
 of the regulations Is permitted, so that
 if any abnormal fiuctuation is detected
 in the motion of the magnets a suspicion of its meaning will be excited in the
 mind Of the scientist who afterward ex-
 smines the photographic trace
 In spite of the delicaey of the appa- ratus. it may seem surprising to the lay mind that the passage of trolley cur rents at a distance of many rods from the observatory should be able to affect tbe instruments within But they do. and it is impossible to separate ID the record the variations produced by genu- inc changes in terrestrial magnetism from those which are caused by the trolley. Professor Rucker said a few days ago: From all parts of the world we hear of observatories ruined or threatened by the invasion of the cleo trical engineer. Toronto and Washing ton have already succumbed, Potsdam, Pare St. Maur, Greenwich and Kew are besieged, and the issue largely depends upon whether these great national ob- servstories can or cannot make good their defense.
 Although the practical service to mankind which is rendered by institu- tiOns of this class is alone sufficient to justify their maintenance and to war rant alarm as to their future, there are other questions involved which possess profound interest for the philosopher We know that the earth is a magnet, but as yet no one is able to say what makes it so. The fundamental secret of 1 terrestrial magnetism has not been solved. Then, too there are various changes in direction which mark the 1 behavior of the needle that remain to l be explained What influence is it that ] makes the needle swing to and fro to a I microscopic extent every dayi Why is it ] that the diurnal swing is greater in | years of sun spot abundance than at the 1 minimum stage of solar activity Why | do the indications of the needle differ I in summer from those of winter? What | is the key to the mystery of the long | period movement that makes 1t neces- sary to reohart the situationf What | causes the eOnyulsive behavior of the I magnets for few hours or days when l there is a great outbreak of sun spotsg 1 And is there any relation between the | weather and the fluctuations in the | earth's magnetism? There are theories l on these subjects, but no generally ao- cepted doctrines and the human mind l is so constituted that it will not rest | until further light is obtained--New York Tribune
 The Belgian King, the first vesse | of the new ocean steamship line be tween San Diego and Japan, has ar rived at the former place with 200t carloads, or 4,0O0 tons, of goods of various kinds, all of which will leave San Diego over the Santa Fe road. There IS an equal amount of goods there which is now being loaded into the same vessel, which will sail next i or Tuesday on her return trip to Japan.
 The Phenix Republican, while nol any name, evidently in- tends the following solar plexus blow f,r G,v.r.I MIL -..-.-k zgf