78 



BAGTERIOLO&T. 



end 1 is then folded over to 1', forming the fold 5 ; 



1 and V are each then brought to 5, thus forming the 

 folds 3 and 7 ; 1 is then carried to the point 7, and the 

 fold 4 is formed, and by carrying 1' to 3 the fold 6 is 

 produced ; and by bringing 1 to 3 and 1' to 7 the folds 



2 and 8 result. 



Thus far the ridges of all folds are on the side of the 

 paper next to the table on which we are folding. The 

 paper is now taken up, and each space between the 

 seams just produced is to be subdivided by a seam or 

 fold through its centre, aa indicated by the dotted lines 

 in Fig. 13, but with the creases on the side opposite to 



Fig. 14. 



that occupied by the creases 1, 2, 3, 4, etc., first made. 

 As each of these folds is made the paper is gradually 

 folded into a wedge-shaped bundle (Fig. 14, a), which, 

 when opened, assumes the form of a properly folded 

 filter seen in b, Fig. 14. Before placing it upon the 

 funnel it is well to go over each crease again and see 

 that it is as tightly folded as possible, without tearing it. 

 The advantage of the folded filter is that by its use a 

 much greater filtering surface is obtained, as it is in con- 

 tact with the funnel only at the points formed by the 

 ridges, leaving the majority of the flat surface free for 

 filtration. 



