976 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



plate iuto the liqiiid, in a gentle current, hy proper means, the 

 deposit or cr3^stallization on it was effectively prevented. 



The next step was only a verification of the old experiment, 

 that vapor of water, containing certain salts in solution, is always 

 positive electric; see Peltier in the above mentioned work, third 

 series, io7ne iv., j). 1414; see also Daguin Physique^ tome ii. y. 555. 



All that we have to do, therefore, is to collect in the shell of 

 the boiler this positive electricity of the steam, so that it can dis- 

 charge in the Avater at every place where the boiler is in contact 

 with water. The interior surface of the steam room of a boiler 

 will not absorb the electricity of the steam, except when it is pro- 

 vided with points, or where, by cold, the steam is condensed 

 against it, in exactly the same way as the metallic roof of a build- 

 ing will not absorb the electricity from the atmosphere which the 

 pointed lightning rods will easily do, and thus protect the build- 

 ing, or which falling rain will also partially accomplish. 



Consequently, I came to the conclusion that all that was prac- 

 tically wanted to prevent incrustations from forming, was simply 

 to place in the steam room or steam-drum of the boiler a number 

 of downward pointed lightning rods, which with their upper end 

 form a metallic connection Avith the boiler. Those points will then 

 absorb the positive electricity of the steam, communicate it to the 

 shell of the boiler, from where it will naturally discharge in the 

 water where this is in contact with it, and everywhere repel the 

 electro positive deposits, so that these are continuall}^ prevented 

 from settling, and kept in suspension in the water, and from time 

 to time may be blown off like mud. 



On this principle an application for patent was made, disclaim- 

 ino; every particular claimed by others, as well in theory as m 

 practical arrangement ; and the patent was granted February 12, 

 1867, No. 62,093, with the following disclaimer and claim : 



"I disclaim any conductor suspended or not by isolated attach- 

 ments. I disclaim a conductor armed at one end with steel points, 

 magnetized or not magnetized — this being not only useless but 

 absurd. But I 



" Claim : The attachment within the upper part of the steam 

 room of a boiler a number of short rods, resembling straight or 

 curved lightning rods, or their equivalents, intended to carr}- the 

 positive electricity of the steam to the bottom of the boiler, where 

 it, discharging in the water, repels the electro-positive deposits, 



