680 Tbansactioks of the A3ierican Institute. 



Mr. Carey Lea states that an ingenious combination of the malt 

 and albumen processes has been made by putting the white of an 

 tgg into a tumbler of ale (previously beating it up and letting it 

 subside), then filtering and using it as a preservative. This method 

 is affirmed to give exceedingly soft pictures, and with adequate 

 exposure, certain absence of harshness of 'contrast. 



THE RODMAN GUN. 



The Engineering of July 5th, states that the gun sent to Eng- 

 land for trial has stood the preliminary test with results eminently 

 satisfactory and to its credit. 



SOLAR PHENOMENA. 



Mr. Hofrath Schwabe, not long since, called the attention of the 

 jistronomers at Kew Observatory, to certain phenomena on the sur- 

 foce of the sun, which he had noticed since last December, and 

 which he recollected to have occurred before, but only at the time 

 <if a minimum in the number of spots. These phenomena are an 

 tibsence of faculae or faculous matter, as well as of the scars, pores, 

 and similar appearances usually visible; also, an equal brightness 

 of the whole surface of the sun, the limb being as luminous as the 

 center. 



A NEW EUDIOMETER. 



Prof. Cooke, of Harvard College, has constructed a cheap eudio- 

 iQeter, to be used in the lecture-room, as well as laboratory, in 

 which the article called " stopper cord," manufactured by the 

 Boston Belting Company, has been found very serviceable. The 

 stopper cord consists of conical rolls of very elastic rubber, about 

 four feet in length, and varying in diameter from one-half an inch 

 at one end to an inch and a half at the other. Stoppers of any 

 diameter between these limits may be cut from the roll and bored 

 with a common brass-cock borer, which must be moistened with 

 water to prevent adhesion to the rubber. The stoppers are found 

 to be air-tight under a pressure of fifteen pounds to the inch, pro- 

 vided the contact between the tube and stopper is at least half an 

 inch in length. 



MAGNETIC PHANTOMS. 



S. Meunier describes, in the Paris Cosmos, a plan for preserving 

 a representation of the curious figures produced when iron filings 

 lire scattered upon a sheet of paper placed over a magnet. He 

 satui'ates the paper to be used, with a warm solution of ferro-cya- 



