383 



TABLE 3. 



Showing the quarter-hourly co-ordinates of altitude of the average 

 semi-diurnal lunar sjjring tidal leave at Chicago, on Lake Michi- 

 gan^ as derived from 1200 observations, made at and near the 

 several periods of conjunction, and opposition of the sun and 

 moon, hefween January Sd and June 2d, 1859. 



