Mechanical Science, 107 



joints are not made by bolts, but one end of a pipe is inserted into 

 the mouth of the next pipe, then the space for the interposed sub- 

 stance should be as small as possible, and the substance one which 

 swells when in contact with water. 4. The lenj^th of the joints should 

 be considerable, both to prevent the escape of water and the flexure 

 of the system of tubes. 5. To ensure tightness, the stuffing* should 

 be confined between a ring fixed to the end of the pipe, and a move- 

 able ring sliding on the tubes. 6. That this precaution may be 

 dispensed with by laying the pipes down in the coldest part of the 

 season. 7. That pipes put into the ground should be supported at 

 intervals by firm props of masonry, to prevent those inflexions 

 which otherwise occur, and form ruptures. 8. That in large towns 

 it is advantageous to place these pipes in subterraneous galleries, 

 either such as are made on purpose, or else in the sewers. 9. That 

 galleries have been tried advantageously for 20 years, and therefore 

 should be resorted to, that those derangements of the pavement and 

 inundations from broken pipes which are consequent upon the 

 ordinary mode of proceeding, may, from henceforth, be avoided. — 

 Globe, April 16, 1828. 



6. — New Razor Straps. — A new kind of razor strap, invented by 

 M. Ferrot, has received the name of euthegone. From the flexibility 

 of leather, a round edge is given to the blade, for which reason 

 paper is used in the new strap. Two kinds of very fine paper have 

 been manufactured purposely, with fine and homogeneous pulp, 

 mixed in the one case with fine emery, and in the other with very 

 fine rouge. These papers are then steeped in melted tallow, after- 

 wards pressed to give them a smooth surface, and then cut into 

 bands, and mounted on pieces of wood properly shaped. Each 

 strap has therefore two faces, one gray, on which the razor may be 

 rendered very sharp, and the other red, which, polishing the edge, 

 renders it extremely smooth. The razor must be laid very flat upon 

 these straps — they improve by a few days use. When ineffectual 

 from age, the surface should be rubbed with a very smooth piece of 

 pumice, or with a little pumice powder on marble or ground glass ; 

 being then wiped with a piece of cloth, they are brought to their 

 first state. — Bull. Soc. Encouragement. 



7.— On the Fusion of Tallow.— The Council of Health at Nantes 

 has been engaged in an investigation of the best means of fusing 

 tallow, so as to avoid the injury and annoyance which arises from 

 an abundant liberation of vapours, when the ordinary method is 

 used. Much pains has been taken in acquiring all the information 

 possible, and numerous experiments have been made both on a 

 large and small scale. The best process which the Council has 

 instituted appears to consist in using, according to M. D'Arcet*s 

 suggestion, a certain proportion of sulphuric acid, and operating in 

 close vessels. By the use of the acid, the fumes always evolved 

 are very much altered and ameliorated in quality, at the same time 



