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Show DEVICE TO HELP IN GEOGRAPHY LESSON A mechanical dories haa jutt beoa eosnpleted br a New Yorker named t'arl Mfck that will toll in an inatant tbc . soltitioa of many question on mathematical mathe-matical geography and at th name timo ao thoroughly explain itself that a pama with but tho slightest knowledge of suck studies ran understand it at onro. Tho contrivance, ita inventor says, la able to teach comprehensively ia an inatant things which ordinarily . require the de-rating of many your a of a person 'a life to study. The machine ia comparatively a simple sim-ple affair, being operated by the slight -amount of electricity prodnced by v-, v-, era! small hatteriea. Jt i called the " tellurian." When oeen in his office the other day Mr, Mack described hie maehiae and the principles of its workings. He . aaid: la the stndr of mathematic geography geogra-phy a globe which baa denoted upon its urfar the principal sections of land and water and the dividing circles is tho moat natural representation of the earth 'a surface, and it affords indie putahly to the student's mind a bet ter conception of this branch of knowledge knowl-edge thaa a flat map would give. " The relatire morements of the earth and the moon around the sun andfhe phenomena depending there-1 upon are evaa more difficult aubjeeti to illustrate, and to attaia a mental grasp thereof by means of eharte or pictures baa always beea a most un satisfactory task.. "In this tellurian the diurnal motion of the earth around its axis from west to east is imparted by means of a handle lerer extending from that por tion of the device which supports the globe. "The daylight, twilight and night on the different portions of the earth are clearly distinguishable ss the rays emitted from the source of light strike the globe; also it can be seen tlia: the places to the east of us have aun rise and midday earlier thas we, and places to the west later. "At each revolution tt globe passss one of the graduations on the outer edge of the stationary dial, which also registers the lapse of a day and a night. These graduations collectively constitute 36S days for. the yearly motion mo-tion of orbit of the earth globe. The inclination of 23(4 degrees of tbo earth's axis is truly represented by the apparatus, which makes It very eon veaient in explaining the apparent motion mo-tion of the sun whan tha latter seems to more northward in summer and southward in winter. "While the earth globe describee its orbit the moon revolves around the globe twelve times. Each complete revolution rev-olution of the moon constitutes one month, which is denoted by a corresponding corre-sponding graduation oa the stationary "By the peculiar arrangements of the mirrors and flaring aides in tha housing hous-ing plaeed ia the middle of the ap naratua the light emitted therefrom is steadily concentrated upon the globe, and suck rays aa would fall beyond the globe are prevented from issuing. This feature will readily be appreciated by the demonstrator or Instructor, as well aa by the pupila, ainea none of the light outside of what ia thrown upon the globe la permitted to diffusa dif-fusa ia the mooa aad diminish the 11-luetratare 11-luetratare effect. "Tsle la especially valuable, for ia stance, while illustrating a aolar eclipse), when the shadow of the moon thrown oa the earth globe la sharply defined, aad the student haa impressed upon bis or her mind a true repre-eentatioa repre-eentatioa Instead of aa imaginary pic tora." |