Polytechnic Association Proceedings. 755 



WIARD'S STEAM SAFETY APPARATUS. 



Mr. Norman Wiard said he had just passed over a portion of the 

 Pennsylvania railway, and was on a locomotive which had on his 

 apparatus for equalizing the heat of the steam in the boiler. Imme- 

 diately after leaving Harrisburg, the water was blown out of the 

 boiler to about eight inches below the crown sheet, and then the 

 water injector was applied, which filled the boiler before reaching 

 the next station. His apparatus prevented the fusible plug from 

 melting, showing that he was thus able to difiiise and equalize the 

 heat. This apparatus, which has been fully described in a former 

 volume of the Transactions of the American Institute, carries the 

 water from the bottom of the boiler into the top of the steam 

 chamber, and the greater the difierence in the temperature, the 

 quicker will the exchange take place. 



The next Thursday being Thanksgiving day, the Association 

 adjourned to the first Thursday in December. 



December 5, 1867. 



Prof. S. D. Tillman in the chair; J. Wyatt Rkid, Esq., Secretary. 



A laro-e audience had assembled to hear the discussion on that 

 branch of the art of tanning of leather which relates to the process 

 of extracting the virtues of tan-bark. Mr. Abraham Steers read 

 the following paper on 



LEACHING BARK. 



Gentlemen: I feel much pleasure in meeting those who this eve- 

 ning give me an opportunity of offering to them some explanations 

 of certain patents, and of making some general remarks on the 

 leaching or spending of vegetable substances. 



And as it is important to me that these explanations and remarks 

 should, without mistakes, reach others who have not so favored 

 me, I have concluded on reducing^ them to writinor. 



With all classes of tanners, the consumption of bark enters so 

 materially into the manufacture of leather, that to them it is unneces- 

 sary to expatiate on the importance of obtaining therefrom all its 

 tanning properties, before they decide that its further exhaustion 

 is to be considered profitless; nor on the importance of the adop- 

 tion, by tanners, of such a system of leaching as will not fail to 



