184 Tbaxsactioas of the American Institute. 



on the march to Atlanta some rebel prisoners (old graduates of the 

 academy) expressed their astonishment at the wonderful rapidity with 

 which the railways were reproduced. " "While bridges were yet burn- 

 ing your men had often commenced their reconstruction, and before 

 the cannon were out of hearing trains were crossing them." The 

 reply was that General Sherman had duplicate railroad bridges 

 always ready. But said another, " Your progress will be arrested at 

 Tunnel Hill, for we have blown up the tunnel." " I doubt it," said 

 a companion, " for the Federals have also probably a duplicate tunnel 

 on hand." The application of steam to the various purposes of manu- 

 facture, is worthy of a lecture by itself, and one can only realize its 

 extent when passing through the numberless workshops in our 

 Eastern cities and villages. I shall say no more on this subject at 

 this time, except to call your attention to the recent successful move- 

 ments to apply steam power to agriculture. We have seen the result- 

 ing benefits from the introduction of the mowing machine, cultivator, 

 and reaper, but we are soon to witness all of these as well as plowing 

 done by steam power. The effect of this will be to bring thrice tho 

 number of acres at the west into use, and increasing the crops more 

 than three times as much as now. 



Telegraphy. 



Telegraphy ma}--, with propriety, be considered one of the branches 

 of engineering, and is peculiarly of modern development. A clever 

 writer says that it may be read b}" each of the five senses. On land 

 lines each signal is made by suspending the flow of the electric cur- 

 rent, for two difterent intervals of times, called " dots and dashes" — 

 the use of which, in dilFerent orders, constitutes the alphabet of the 

 telegraph. When these are printed they are read by " sight," but 

 ordinarily the operator reads them by " sound," as easily as the musi- 

 cian reads the letters of the scale by the same sense. If the operator 

 has no instrument, he will grasp the wire in his hands, and read the 

 signals by " feeling" the intermissions of the flow of the electric cur- 

 rent. In like manner, by placing the wire across his tongue he can 

 " taste" the same intermission (but this is a dangerous experiment). 

 And it is said that the electricity can be made to dissolve a chemical 

 and produce a pungent odor in the telegraphic alphabet, which can 

 be read by " smelling," but for this I do not vouch. I believe that 

 the method of signaling through the Atlantic cable is known in 

 detail to but few persons. The operation is exactly reversed from 



