ABSTRACT
In this investigation, the effect of season, time of the day and topography has been examined. Two lines, one on water of length 1098.650 meters and the other 1287.05 meters on land were selected for the study. Coefficient of refractions on these two lines for different time of the day - 0800 hours to 1600 hours and for different seasons - dry and wet seasons were computed. Analysis of data revealled that variations of refraction on the two lines was less in wet seasons than in dry season. Also refraction was found to be minimum and more steady between the hours of 1200 - 1600. This confirmed the statement found in most text books and survey literatures. The values of coefficient of refraction obtained from this study are higher than the traditional values. This may be due to the fact that the lines are relatively short. The importance of meteorology in high order work is much emphasised.