THE LTME-IJGHT 65 



felt by an almost imperceptible click. The whole lime is thus 

 traversed in one continuous spiral from top to bottom, each 

 halting-spot on the surface being exactly marked out. The 

 whole jet is shown in proportion, with the further addition of 

 a ' cut-off ' arrangement devised by Mr. A. Pringle, in fig. 65, 

 p. 118. 



Mr. E. G. Wood has also constructed a jet with a click or 

 check mechanism, so arranged, that when a second revolution 

 of the lime takes place, the places where the jet impinges are 

 half-way between those of the previous revolution. In this 



Fi<5. 43. Lime-turning arrangement 



way less perpendicular motion of the lime becomes necessary. 

 There is another screw motion, with a separate handle, for 

 adjusting the distance of the lime from the jet. The jet 

 itself is packed with gauze, and the tube and nipple are bent 

 like an elbow, which Mr. Wood considers to produce a better 

 mixture of the gases. As will be seen, my experiments and 

 they have been long and many have led me to a different 

 conclusion on this point, and moreover such nipples cannot 

 conveniently be employed of different sizes, which is very 

 desirable. The lime-turning movement is, however, ingenious 

 and good, and this jet would doubtless be more widely used 



F 



