Miscellanies. 171 



When the wind is variable, the hood is liable to rattle against the 

 cylinder, and occasion an unpleasant noise. This may be prevented, 

 by punching holes round the cylinder, and attaching to it, by means 

 of wire, a band of thick list or double piece of cloth. The hood 

 must extend at least an inch below the top of the cylinder. 



10. Method of coating Busts and Plaster Casts, so as to give 

 them the appearance of marble; by M. Pleuvarre. (J. G.) — Into 

 a wooden tub or trough, put a strong and warm solution of alum. 

 Into this plunge the bust or plaster cast, previously made perfectly 

 dry, and let it remain therein from fifteen to thirty minutes ; then 

 suspend it over the solution, that the superfluous portions may drain 

 off, and when it is cold, pour over it a fresh portion of the solution, 

 and apply it evenly by a sponge or cloth. Continue this operation 

 until the alum has formed a crystallized coating over the whole sur- 

 face. Put it aside, and when perfectly dry, polish it with fine sand 

 paper, or glass paper, and complete the polish with a cloth slightly 

 moistened with pure water. 



A wooden vessel is best for the solution, warmed by steam from 

 a boiler, because metals are apt to color the solution. This coating 

 gives greater solidity to the substance, and possesses the whiteness 

 and transparency of the finest marble. It stands the attacks of mois- 

 ture in any apartment, — is less subject to become soiled, and is as 

 easily cleaned as marble. 



In this manner, excellent copies may be obtained of antiques, as 

 well as moderns, at a price little exceeding common plaster casts. 



11. Iron Cement. (J. G.) — The Fountaineers of Paris, make use 

 of an iron cement, for uniting the stones which form their fountains. 

 It is very strong, and may be employed in a variety of occasions. 



Take one part of vinegar, and four parts of pure iron filings, stir 

 them well together every hour for six hours, or until the mixture 

 begins to form a good paste. To unite stones by this cement, 

 clamps are to be first attached to the stones, which are to be very 

 dry. The surfaces (of the stones.) to be united, need not be more 

 than two lines (at farthest,) apart at the top, and to terminate below 

 at the depth of five or six lines, at the distance of one line. The 

 mastic once introduced into this space, the stones are to be pressed 

 together, and the cement allowed to set. In a few hours, the sur- 

 face may be polished, and the joint becomes as firm, as the stone 

 itself. 



