4 o6 SECTION-MECHANICS. 



The PRESIDENT : I rise now to propose a vote of thanks to Mr. 

 Hackney for his interesting communication, which I am sure you will 

 accord. 



I will now call on Mr. Preece for his address on Electric Telegraphs 

 a subject of vast interest and great detail. I fear Mr. Preece will 

 not have as much time as we should like to give to it, but I have na 

 doubt he will make it interesting. 



ELECTRIC TELEGRAPHS. 



Mr. PREECE : Mr. President, ladies, and gentlemen, telegraphy is 

 the art of conveying the first .elements of written language to distances 

 beyond the reach of the ear and the eye. When electricity is used to 

 effect this operation we have the electric telegraph, and inasmuch as 

 there are many fundamental phenomena of electricity which are used 

 as the bases of these telegraphs, so we have these telegraphs divided 

 into different systems. I propose to show you how these systems of 

 telegraphy have grown by a principle of evolution from the first in- 

 cipient idea to the present almost complete form of perfection by 

 stages of growth which will be represented by instruments displayed 

 in this noble collection. The invention of the telegraph cannot be 

 claimed by any one, for the simple reason that the very first idea con- 

 veyed by the notion of electricity and its action at a distance must 

 have given the first idea of conveying information to a distance. 

 Electricity, or that form of electricity which is used namely, voltaic 

 electricity dates from the commencement of this century. In the year 

 1800 Volta developed that instrument that is called the voltaic pile, and 

 which has been the parent of all our batteries. In the same year, 1800, 

 Nicholson and Carlyle discovered the decomposition of water by the 

 aid of a current, and in, less than nine years the combined notion of a 

 current of electricity and the decomposition of water led to the first 

 electric telegraph. 



Professor Sommering of Gottingen by means of this little 

 apparatus here, which is the original and identical apparatus made 

 and constructed under his own eyes by means of thirty-five wires 

 connected between two places, by means of a series of little points 



