158 fHlLOSOFHICAL TRANSACTIONS. [aNN0 1757. 



He also made several experiments, by lowering the horizontal pipe 2 feet undo* 

 the surface of the water, and raising it at different times to within 4 inches of 

 the surface, and could not at any depth force the air through, while the engine 

 worked ; but on opening the steam-pipe, which is a pipe for letting the steam 

 pass from the boiler whenever the engine stops, the bellows could then readily 

 force the air through, though the water boiled ever so strong, and seemingly 

 made a surprising increase of steam. It is a very doubtful matter, whether air 

 forced through boiling water would have answered the purpose intended : but he 

 believes it was never imagined, that air could not be readily forced through, 

 until proved by the foregoing experiments. 



XLF'I. Observation of a Lunar Eclipse, March 27, 1755, at Lisbon, By 

 Father J. Chevalier, F. R. S. p. 374. •, ,,<i 



Beginning of the penumbra. 10*^ 29*" 50* 



Beginning of the eclipse, doubtful JO 33 35 



It was now certainly begun .10 34 5 



The total immersion 11 33 50 



Beginning of the emersion 12 4 38 



End of the eclipse 13 13 2 



End of the penumbra, doubtful 13 16 50 



XLFIL Observations of a Lunar Eclipse, Feb. A, 1757, ^c. at Lisbon. By 



Fa. J. Chevalier, F. R. S. p. 376. 



Beginning of the penumbra 4*^ 52"* 49* morn. 



Beginning of the eclipse, doubtfiil 4 55 29 



It had now certainly begun 4 57 30 



Clouds prevented further observations. 



Observations of the Eclipses of Jupiter s Satellites. 



An. 1757, March 21, the 1st sat. immersed 11^ 13™ 1« aflem. 



22, the 3d sat. immersed O 13 32 morn. 



XLF^llL Observations of the Eclipses of Jupiter s Satellites at Lisbon, in the 

 Year 1757. % J- Chevalier, p. 378. 



June 7, the 1st sat. emerged 10** 29"* 21' aftern. 



8, the 2d sat. emerged 8 32 48 aftern. 



8, the 3d sat. emerged 9 36 25 aftern. 



15, the 2d sat. emerged 11 6 15 aftern. 



16, the 3d sat. immersed O O 29 mom. 



