| Show JsClESCE WHAT IS IT THAT SOW rBODCC REMAKICABIi JNV ESTIO > S Philadelphia Pro Dwellers by Ube toa have noUceil lor ngt that tlielrvriudon janerlgrow dull by the sand blow against them Genera II C Tilfehmau of PJiilatlelphl about twenty years ngowas the fiat to sec how much tills familiar fact meant He thought that if a little rand lightly blown ngaiust gluts cuta its surface the operation could Lc reduced from years to minutes its great Jest of sand were blown against the glass by pressure His experimiuts proved his surmise to be true and now in hundreds of Sac lories throughout the country the sand blast is I busy not onlycuttin glass for omatrental purposes but tlmjlus granite for builders and finishing tillS of hard steel for tool shops ihoiaben one tlrikes n common sulphur sul-phur match the phosphorus burns with a purplish flame then the sulphur with a yellowish hue dad last of all the wood glows with reddish red-dish rays From noticing that every substance jklJa its own recuh color in burning t Sir John I xhel ilIon il-Ion ago ug s < > tcj that these colors might serve to iiientlfjr the S1b ttauces fchowiu them Some tlwe after he threw out tho cuggcjU the spectroscope was devised and now by its aid we nrealileto tell why Its elements are aglow not only lu the tun but In the burs as welt That oil repels water would not sear to be a very promising fact for an Inventor to begin with Yet It enabled Seuifeldcrtoglve the world lithography lie found that wrlUtlg executed In oily ink could be trans ferret to tone n that hu could print from the itnrt3lou When ink from a roller was applied to it the oily lines received tho Ink as all the rat of the stone was washed with water Inn Ink lodged nowhere eke aeveril beautiful printing process rla ell on photography depend on a principle as simple as SencfelJire namely that certain gelatine com lounds are rendered Insoluble by the action of light A picture taker on a Com ouna of this kind is carefully care-fully I washed L braving I In relief every attic au which light has fallen It has glen recently iliswver that fctrong aa alee i + it can be I made et stronger by an alloy of 3 or 4 per cent of nickel This means that In the future we can hare I larger bridges higher towers and Ihjutbr mtthinery than ever Ship owners and the passengers as well have had no email cau e ofauxlet I in the Hiscerlibllity to magnetism of the iron fo largely uwd in Hlllp I binding It would Rem that the chief source of error in compas mi boon berenoved aait Is found that a little manganese alloyed with i iron products a metal with scarcely auy capacity at all for inagnetUn jJt1Aibt11itl llo Lrcured i by an inccuius jiroc < 93 which coat them with a magnetic oxide of Iron Tim ei ltiYUcts of electrical al > paratus to Uiangesof temperature has been employed not onl > in constructing con-structing automatic lire alarms but JllO to give notice sliiplioard 01 ajipiraclilni ictl > trgs AnJ electrical elec-trical appliances can be used not only to regf < Ur and give notice or temperature but also irialioue In light sound and every form of force aud this in degrees of the utmost ut-most minuteness Indeed ro sensi tie is Prof Bells botojiione to changes in the intensity of light that he tan find no artificial source of Illumination which does not create cre-ate a continuous note In It Since the approach of an ironclad ship can be clearly Indicated by a deli tate electrical appliance 3 rangefinder finder has bvcu addixl to the resources re-sources of the United States navy whereby its gunners can correctly fire at a chip they cannot see Photography today i rforms automatically mztlcally a thousand services for ua which a century ago were the boor IOUR toll ofdraughlsmLn and artists It does yet more In cameras of the instantaneous pattern we are now able to catch pictures of birds in the act of flight horses is they trot or galloppictures which show art that many of its conventional atU tudes are faKe What were consld crud mere grotesques the art or Japan in its representations of animals mals in active motion are now found to be due Imply to more careful olrirvatlon than tbat cf the western world It is only in recent years that inventors have begun to understand he full meaning of the old proverb Uiat it Is a p poor rule that will not work both wayp A turbi wheel much the best device whereby where-by > to derive power from a head or water a turban wheel reverted In motion is one of the most efllclen water lifters an engineer can uc jrammc a Frenchman invented what U perhaps the best dynamo for obtaining electricity from mecban cal power His dynamo rcversu L s a capital means of getting mechanical me-chanical power from a current Sometimes a fact of tile common ft kind gives inventor a golden lint The descent of a maple reed In the air gave the idea of a screw propeller to Its inventor A new invention so far from in any degree exhausting what remains to be uund but lights up a new horizon for exploration It Is like a new octavo oc-tavo la music which multiplies tbe musicians possibilities in romped tion by the whole width of his gamut Or like all extension of the visible spectrum which would enlarge en-large at a bound tIle whole realm ort o-rt and of color |
