134 



APPENDIX. 

 TABLE II. Extreme radius = 10 ; Depth of float = 2-5. 



The following is a type of the calculation of the power by means of the centre of pressure. 

 Let it be required to find the power exerted by the engines of the ' Salamander ' in the case 

 proposed at page 127. 



The radius of the paddle wheels being 10ft. Gin., the position of the centre of pressure 

 cannot be found immediately by referring to either of the preceding tables, in which the radius 

 is assumed equal to 10 ; we must therefore first find the numbers which represent in the tables 

 the depth and immersion of the floats, and the radius of the rolling circle. The depth of the 

 float is represented by the number 2*38, the immersion by the number 5'238, and the radiiis 

 of the rolling circle by 7'247. The depth of the float being intermediate between those 

 assumed in the tables, we must first enter Table I. ; and in the column under the immersion 

 5'25, and opposite to the numbers 7'2 and 7'3, in the first column on the left, we find the 

 numbers 0'545, 0'546, of which we take the mean, 0'5455 ; then in Table II. we do the same, 



