MECHANICS AND USEFUL ARTS. 83 



2. In the neighborhood of the new house, several rooms are selected, which 

 have been inhabited already a considerable time, so that the sanitary con- 

 dition of the latter can be ascertained ; after that, of their inhabitants. In 

 this selection, care must be taken that among the inhabited rooms in which 

 the experiments are to be made, there be both those which are well ven- 

 tilated, dry, and healthy, as well as so badly ventilated, and so damp, that 

 the effects thereof be apparent on the inhabitants. 



3. Twenty or more rooms in the new house and in the neighborhood being 

 thus selected, an equal quantity of vessels of precisely the same capacity, 

 form, and opening, are filled either with fresh-burned quicklime, coming 

 from the same kiln and finely pulverized, or with sulphuric acid of com- 

 merce ; five hundred grains is about the right charge for a vessel, either for 

 lime or for the acid ; but it is necessary, in either case, that the charges be 

 weighed with the most exact balance. 



4. The vessels thus filled have to be placed in all the selected rooms. 

 Trustworthy persons have to care that said vessels be placed in the 

 midst of the rooms, and that windows, chimneys, and doors, be carefully 

 closed as soon as the vessels are thus placed. In rooms to be furnished 

 with bedsteads close to the walls, the above vessels are to be placed close to 

 such walls. 



5. Twenty-four hours after the exact moment of the location of the first 

 vessels, the removal of all the vessels is to take place in the very order of the 

 location, and all of them are to be transferred into a room where each in its 

 turn is to be weighed. This is to obtain the exact weight of each, twenty- 

 four hours after its location. The weights at the moment of location, and 

 those twenty-four hours after, are carefully recorded for each vessel, each of 

 them being marked with a separate number corresponding with the number 

 of the room hi which it was located. 



If the numbers recorded by this process be then examined, it will be found 

 that the weight has increased ; and if then the amount of the increase in the 

 rooms of the house newly built, be compared with the amount of the increase 

 hi the several rooms of the neighborhood, due consideration taken of the 

 sanitary condition of the latter, such comparison will indicate at once and 

 with infallible security, whether any part of the new building, and which part, 

 is dry enough to be used as a dwelling without danger to the inhabitants. 



IMPROVEMENTS IN THE MANUFACTURE OF MILITARY IMPLE- 

 MENTS, &C. 



In the recent Crimean war, great difficulty was experienced by the English 

 Ordnance Board, in transporting gunpowder to great distances in a dry con- 

 dition. Some of the powder hi the Crimea having become damp in its transit, 

 had to be removed from the barrels with pickaxes. The powder is now sent 

 over in vulcanized canvas bags contained in barrels. The bags subsequently 

 served many useful purposes. 



Among other recent improvements in Military Science brought out in Eng- 

 land are the following : wooden barrack buildings are rendered fire proof, or 

 nearly so, by successive applications of soluble glass and lime wash. Minie 



