WITH NOTES. 447 



or other material. The least pressure on the oiitside 

 of the large oval, will extend the nippers &, d, which 

 again close when such pressure is removed. 



But there may have been another form of such tongs, 

 like the letter X, or two such figures combined ; and by 

 increasing the series we should produce the instrument 

 known as the lazy -tongs, which collapse into a very 

 small space, yet will extend to a great distance. 



5 0. 



A complete light portable Ladder, 

 which taken out of ones Pocket, 

 may be by himfelf fattened an hun 

 dred foot 4 high to get up by from 

 the ground. 



4 feet. P. 



\_A Pocket-ladder. ~\ There are many curious and 

 ingenious designs for portable scaling ladders, offered 

 by Vegetius in &quot; De re militari,&quot; 1535, but which would 

 require to be very considerably modified to become 

 pocketable; however, they occur in every variety at 

 page 35, in short pieces, each with a screw at one end, 

 and a socket at the other ; at p. 59, as a neat rope ladder ; 

 at p. 113, on the principle of the lazy-tongs ; and at p. 

 162, a method of connecting short poles is exhibited. 



Eobert Fludd, in the second book of his works, pub 

 lished in 1617 and 1618, folio, page 414, gives a large 

 copper-plate engraving of a very ingenious form of 

 ladder. Each step is of wood, and the two sides of 

 rope. The ingenuity of the invention consists in each 

 step having a ferrule at one end, and the opposite end 

 tapered sufficiently to fit into each ferrule of the adjoin 

 ing step ; by this means the whole can be put together 

 like an ordinary fishing rod, and the top step terminat- 



