716 TECHNOLOGY AND CIVILIZATION. 



We may now turn, without anxiety lest we sacrifice clearness, to the 

 side of the most modern of all technical novelties, the electro-mechan- 

 ical. Here we recognize in the Galvanic battery, or chain, a chemical 

 runningworl-, which expression can well be conceded, as it depends upon 

 motion excitement, although it beatomical ; the induced physical-elec- 

 trical stream, the valves of which are the obstruction ratchet, the con- 

 tact, polishing springs, etc., is used in various arts; in telegraphy it 

 works in leap work of the second order, provides by relay for release 

 and making fast again, and a mechanical runningarrangementof writ- 

 ing work ; i t results, according to circumstances, from the third to the 

 fourth order. 



The usual sound-contrivances of the railroad work in the fifth order, 

 chemically in current producers, physically leaping in the anclior pull- 

 ing through which a mechanical tension work, that is one bent by the 

 hand, is released ; the same drives a check work which again the little 

 hammer tension work (Hammerspannwerke) springs, makes taut, and 

 then releases. 



Among chemical drive work, we notice that the tension works take 

 a prominent place. Those placed here will be of the number so artis- 

 tically prepared by chemists that they give up their tension, or expan- 

 sive force, slowly or rapidly. Gunpowder is the most powerful tension 

 work, which the naturistical groping Middle Age set in the place of the 

 mechanical tension work stretched by the hand of man out of netting, 

 bows, and sinews in large and small throwing machines. The purpose 

 remaining exactly the same, the kind of tension work was changed. 

 The fuse releasing the new tension work was in itself a slow running, 

 chemical tension work, entirely separated from the larger. Later we 

 got so far as to take the two together in a single contrivance, at first 

 in tiint-locks, then in percussion locks. There one entered the third 

 order. The percussion cap, a chemical tension work rather easily liber- 

 ated, is set free by a mechanical tension work attached to the guncock. 

 The ball is thrown by a tension work of the third order, as occurs in 

 the set-trigger in the fourth order. 



Allow me to say a word concerning a petty example, the match. Not 

 two generations have we possessed it, and previous to this brief period 

 we manganists, in point of fire kindling, were very nearly on a par with 

 the lowest naturists. 



In a natural state, as we know, people, through laboriously acquired 

 skill, kindle a fire by rubbing together two i)ieces of wood; in other 

 words, they set free that tension work, heat. The old Greeks used for 

 the purpose the pyreion, the under piece of which, called the eschara, 

 contained a bore, in which the rubbing piece, the trypahou or borer, 

 was inserted and then turned by twisting the hands. 



Ought not in some hidden corner of the Grecian mountains the pyr- 

 eion still to be found? It would be very serviceable to bring it to light. 



The little fire-chests containing flint, steel, tinder, and threads dipped 



