310 Mr A. Beattie's Description of a New Door-Spring. 



ao-ainst. There is a cog or stop F on the under wheel, which 

 moves in a groove or slit, cut in the upper wheel, to prevent its 

 being forced too far round. 



In the same manner, when the lever or door is opened to the 

 left, the upper wheel A is forced round, until it is stopped by 

 the coo- F on the under wheel, which pulls round its chain and 

 lever, and is pressed back again by the opposite spring E. 



In this manner the wheels change the action upon the springs 

 bv the door being moved to the right or left. 



The object of the inventor was to make this spring go into 

 less room and at less expense than the one at present in general 

 use. It has also the advantage of being less liable to go out of 

 order, and can be made to turn more than the quarter circle, 

 which the other cannot. 



The box may be filled with oil, or the working points oiled 

 occasionally, by removing part of the cover. 



N. B. — By enlarging the diameter of the wheels, and strength- 

 ening the other parts in proportion, the spring can be made to 

 suit any size or weight of doors. 

 Edinburgh, 11//j December 1833. 



Report of Committee of Society of Arts on 3Ir BeaUies Spring-Door, 

 read 9tli April 1834. 



Immediately subsequent to the meeting at which Mr Beat- 

 tie's door-spring was exhibited, it was attached to a swing-door, 

 in the premises of one of the reporters, who has paid constant 

 attention to its action, and who, after a trial of three months, is 

 satisfied that, to its other good qualities, it adds that of durabi- 

 lity. 



Your Committee are of opinion that the construction of this 

 door-spring possesses several important advantages over any 

 other they are acquainted with ; and as, after a trial of sufficient 

 duration, to have shewn latent defects if it had any which had 

 escaped their notice, they see no reason to alter the favourable 

 opinion they had formed of it, they humbly propose that Mr 



