= the transmission coefficient. 
668 Proceedings of the Royal Society of Edinburgh. [Sess. 
“ n ” = total number of vanes of the paddle-wheel. 
4 20 15 12 10 O 58c8 7 6 5 
“^” = the eclipse-angle. 
CHART II. 
In order that the chart should be on as large a scale as possible, it has been necessary to draw the lines for 3-vaned 
and for 4-vaned paddle-wheels in two parts. These lines, it will be noticed, run out at the right-hand side 
and reappear at the same height on the left-hand side. The lower row of figures (within brackets) on the E 
scale applies to the additional pieces of the lines. 
1 -t = 
riE* 
360 
ft,” = the total number of vanes of the paddle-wheel. 
