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height above the building, supported by a vertical 

 axis or pole; the lower end of it passes through the 

 roof and ceiling into an apartment below. 

 Fig. 2. The lower part of the pole or vertical axis aa. Fig. 1. 

 more enlarged, to give a better view of the necessary 

 appendages. This pole is made of a slender spar, 

 such as are made use of for strong setting poles for 

 lighters, and handles for boat-hooks, as not being af- 

 fected by lightning, which iron too often is, and the 

 cause of the destruction of buildings and many lives. 

 To this pole is fastened a fr9,me of light wood by 

 screws, in which the weights are confined, one on 

 the top of another, in grooves, in such a manner 

 as to work up and down with the greatest facility. 

 The weights are connected together by cords, and 

 marked 1. 2. 3. 4. &c.; the space between each, when 

 drawn up by the force of the wind, is about one 

 inch, as may be seen by the drawing, and each 

 weighs one pound averdupois. To the top weight 

 is fastened a line, and passing along the pole to the 

 top, and over a brass pully fixed at the bottom of 

 the square tube, under the sliding rod b. Fig. 3. as 

 far as (a), and there fastened: in this sliding rod a 

 groove or channel is cut underneath, to receive the 

 line, so as not to impede its passage over the brass 

 rollers ff. The line is composed of a number of 

 common sewing threads, laid in different directions, 

 well waxed, and inclosed in a cotton case, to prevent 

 VOL. XI. K as 



