514 KANSAS CITY REVIEW OF SCIENCE. 



gives 87.810 miles as the length of the spot; a length 20,000 miles greater than 

 that of the spot of April i6th. 



This measurement is that of the extreme length of the cluster including out- 

 lying spots and penumbra, and is not nearly as accurate as if made with a micro- 

 meter, but is correct, however, within 3,000 miles. 



Study of solar phenomena is one of the most exciting lines of research, and 

 it is to be hoped that with the powerful tele-spectroscopes, now capable of being 

 made, together with sensitive instruments for the detection of magnetic pulsations, 

 a hitherto unknown law of nature will soon be discovered able to solve the 

 .mystery. 



November 20, 1882. 



SOME RECENT IMPROVEMENTS IN THE MECHANIC ARTS. 



BY F. B. BROCK, WASHINGTON, D. C. 



Electric Lamp. — A recent English invention in electric lamps has four mov- 

 .-able circular carbons which are combined with the usual carbon-holder, gear and 

 regulating pinions, frame, armature, and magnet. 



Mining Submerged Rock. — A late inventor has constructed a dredging 

 vessel formed of a rod with two parallel rows of teeth projecting upward and out- 

 ward therefrom and provided with closing end-pieces. It is dragged by a bail 

 pivoted at the ends to the ends of the rod, and limited in motion by guide-slots 

 at the top of the end-pieces. These rows of teeth, or prongs, are symmetrically 

 arranged on opposite sides of the rod so that each set in turn operates to gather 

 • or retain the deposits as the dredge is drawn back and forth upon its one side, or 

 vthe other, over the surface to be dredged. 



Combined Coal-Hod and Sieve. — This novel coal-hod is provided with a 

 removable bottom beneath which is located in horizontal ways a reciprocating 

 sieve. When it is desired to sift the ashes gathered in the hod, the bottom ife 

 swung out of the way so that the ashes fall upon the sieve. 



Electric Incandescent Lamp. — One of Edison's latest inventions com- 

 prises a method of manufacturing incandescent electric lamps, consisting in form- 

 ing the enclosing bulb or globe directly from the molten or pot-glass, forming 

 separately the supporting tube or neck for the incandescent conductor, sealing 

 therein the leading-in wires, attaching the carbon thereto and then hermetically 

 uniting the parts by a welding together prior to the exhaustion of the lamp. 



Safety-Stop for Elevators. — This elevator has in coi:nbination with the 

 suspension rope a counter-balance weight at its end and stop mechanism attached 

 to the car. A safety-rope is employed having one end connected to the safety- 



