128 Notes on Sirius 



as many of the fire-plugs were laid in and on a level with 

 the street water-channels or gutters, sewage and other 

 objectionable matters ran down into the empty pipes, and so 

 contaminated the water used for drinking and domestic 

 purposes. To remedy, or remove, the great danger of 

 spreading disease by the use of such foul water, Mr. A. K. 

 Smith's invention consists of applying a coiled or other 

 spring of steel, brass, or other elastic substance, for effectually 

 closing the orifice, at low levels, against the admission of 

 sewage and other impurities during the absence of internal 

 pressure. The author also suggested that in all lines of main 

 where they were used, there should be at the highest level 

 an ordinary air-valve, so that the air could escape when the 

 pipes were filling with water ; such air-valve or ordinary 

 hydrant to be kept at a higher level, so that no fluid or solid 

 matter could enter the orifice. 



The Society learns with satisfaction that since Mr. Smith 

 has called public attention to the danger arising from the 

 contamination of the water in the street-mains by sewage 

 entering at the fire-plugs, the Government has removed 

 such fire-plugs from the bottom of the channels, to a 

 position more distant, and higher, to obviate the danger 

 pointed out. 



Art. XLI. — Notes on Sirius and its Coii^mnion Stars. 

 (Great Telescope.) By F. MacGeorge, Esq. 



[Read lOth June, 1872.] 



Mr. President and Gentlemen, — Last year was brought 

 before you the fact that some minute stars had been 

 observed in the optical vicinity of Sirius, and it has been 

 thought that it may interest you to hear the detailed notes 

 of these and subsequent observations of this star. 



First will be read two notes of observation of Mr. Le 

 Sueur, made while the mirror was not in so good working 

 order as it is at present. 



]869, Dec. Qth. — "Sirius very unsteady. Looked for 

 Lassel's companion. Can see nothing at; all. Do not know 

 where companion is. 



"Spectrum : F, C, and very fine lines too unsteady. F 

 is very conspicuous, and remains clearly visible by the sky 

 glare, when the star is removed from the slit." 



