60 



Mr. George W. Clinton delivered a lecture on repulsion, 

 as a property of matter. 



April 25. The committee, to whom the bronzed article 

 manufactured by Mr. Smith, had been referred, reported fa- 

 vorably as to his skill and success in this experiment. The 

 report contained a detailed account of the mode usually pur- 

 sued in bronzing brass and iron goods and plaster figures, and 

 also of bronzing in oil colours. The following is the conclu- 

 sion of the report. 



"The method used by Mr. Smith in bronzing; on copper, is 

 by means of an oxide of iron, called purple %rown. This 

 powder is mixed with water to the consistence of cream, and 

 applied to the surface of the article with a brush. It is then 

 heated over a charcoal fire, to a sufficient degree to fix the 

 oxide upon the copper, and when cold, the superfluous pow- 

 der is brushed off, and the article finished bv hammering or 

 rubbing with a brush. The greatest difficulty in the process 

 seems to be in obtaining the proper degree of heat necessary to 

 fix the oxide ; if it be too great or too small, the operation will 

 fail, the copper must be recleaned and the process repeated. 

 A little experience will, however, soon enable the workman 

 to determine the proper temperature." 



Mr. R. V. De Witt gave an account of an improved boiler 

 for steam-engines, invented by Mr. Gallup, of Ohio. Mr. 

 G's boiler is spherical, and the heat is applied in the centre. 

 The principle made use of by Perkins in his steam-engine, of 

 heating the water so that it is converted into steam on escap- 

 ing from the boiler, is adopted bv Mr. Gallup. 



Mr. R. V. De Witt also exhibited an iron rod, the end of 

 which was coated with platina, intended for the extremity of 

 lightning rods on buildings. These rods are manufactured in 

 Philadelphia, and being superior to those at present in use, and 

 particularly in preventing oxidation of the iron, deserve gen- 

 Mr. William J. Coffee, artist of this city, presented to the 

 Institute a bronzed plaster medallion of his Excellency Gov- 

 ernor Clinton, for which its thanks were unanimously voted. 

 Mr. Simeon De Witt read the following communication : 



CONICAL RAIN-GAGE. 

 I shall now submit to the Institute the description of a rain-gage, 



■ , :r. , • • ■ ■ - ^ ■ . n;-,"m 



more accurately than the most approved that has been brought into 



