228 Mr Hicks, On the motion of tivo cylinders in a fluid. [Dec. 2, 



the path of one relatively to the other has its convexity towards 

 that other. If they are equal and touch one another at their 

 nearest distance, the distance of the asymptote of the path of one 



from the centre of the other is ^ / (^ t^j ) x sum of the radii^ 



Addition to Mr Glaisher's paper on factor tables, pp. 99 — 138. 



The accompanying Plate (Plate V) represents, on a reduced 

 scale, the sieves for 13 and 17 described on pp. 131 and 132. The 

 shaded squares are those which are cut out. The 13-sieve is 

 formed of the first thirteen columns of one of the sheets (con- 

 taining seventy-seven columns) and shows the numbers between 

 3,000,000 and 3,000,000 + 13 x 300 which have least factors 7, 11 

 or 13 ; thus, for example, from the third column we see that 

 3,000,613 3,000,739 3,000,823 



3,000,641 3,000,767 3,000,851 



8,000,683 3,000,781 3,000,893 



3,000,697 3,000,809 



have 7 as their factor ; that 



8,000,679 8,000,811 3,000,877 



8,000,701 8,000,833 3,000,899 



have 11 as their least factor, and that 



3,000,647 8,000,751 8,000,829 



3,000,673 3,000,803 3,000,881 



have 13 as their least factor. Of course the numbers such as 

 8,000,179 for which 7 appears in a shaded square, have 7 as their 

 least factor, and are also divisible by 13 ; and similarly, when 11 

 appears in a shaded square, the number has 11 for its least factor 

 and is also divisible by 13. 



In the di'awing of the 18-sieve the margin, containing the 

 figures 01, 07,... is retained in order to show the arrangement 

 of this column of arguments which is described in the first para- 

 graph of § 20, p. 131 ; but of course before using the sieve the 

 margin is cut off as in the 17- sieve. 



The mode of construction of the sieves is explained on in the 

 last paragraph of p. 134. 



1 See Quarterly Journal of Mathematics, Yol. xvi. p. 113. 



