LONGITUDE OF McGILL OBSERVATORY. 177 



The Eussiau transit is 41 feet to the west of the centre of the dome of the llarvard 

 College Observatory of which the longitude is : — 



— ■!'' 44'" 30^993 + .041 



Eednction of dome to Russian transit — 0.040 



JA of Montreal and Cambridge Stations, — 9 41.510 ± .019 



The pier of the transit instrument at the Mt-Gill College Observatory is therefore in 

 longitude 



4'' 64" 18 .643 + .046 West of Greenwich. 



