Academy of Sciences in Paris. 391 



open to objection in warmer climates. The present memoir of M. 

 Blom has for its object the removal of this difficulty. He remarks 

 that, with respect to the variation of temperature and the hygrometric 

 state of the atmospheric air, it is hardly probable that the houses 

 would ever be exposed to greater variations than in Sweden, where 

 the thermometer of Reaumur in July generally marks 20, and some- 

 times 24, above zero, and falls in winter to the same number of de- 

 grees below zero. In the latter case, the temperature of the interior 

 of the houses is preserved, by stoves, at from 12 to 19 above zero. 

 M. Blom points out particularly the advantage derived from the con- 

 struction of the wooden walls, both on account of their small thick- 

 ness and their small conducting power: thus, in thaws, every part of 

 the edifice promptly assumes the highest temperature of the atmo- 

 sphere, and there is not that precipitation of water which is always 

 observed on the surface of stone walls, and which produces a very 

 injurious humidity. It is well known that the Swedish ships remain 

 a long time in hot countries without being at all injured by the heat 

 of the sun, although the surfaces of the decks are not covered with 

 coating; and it appears that the moveable houses of M. Blom 

 have been used for four years in the Swedish colony of St. Bartho- 

 lomew, and no complaints have been made of their having sustained 

 injury either from the heat or the hurricanes which prevail there. 

 These houses are warmed by portable stoves, also invented by M. 

 Blom, and they are insured against fire at the ordinary premium, the 

 offices having been satisfied that, while they are not more liable to 

 conflagration than ordinary houses built of the same kind of wood, 

 they have the advantage of being easily removed out of the reach of 

 danger. Every part of these houses is moveable, so that, with very 

 little expense, the form and position of the rooms may be changed 

 at pleasure. In countries subject to earthquakes, these edifices are 

 particularly desirable, as, independently of the facility of removal, 

 they are much less likely to be destroyed or overthrown than con- 

 structions in stone. But it is in new colonies that their advantage 

 would be most sensibly felt. Wherever it may appear to the settler 

 desirable to 'fix his residence, his habitation is ready, and may be 

 removed elsewhere when circumstances may render a change desir- 

 able. Large public edifices, such as hospitals, barracks, prisons, &c., 

 may in like manner be easily transported wherever a change or in- 

 crease in the territory may render it desirable to remove the seat of 

 government. As far as the mode of construction can be understood 

 from the drawings appended to M. Blom's memoir, it appears that 

 the walls are formed of thick planks, two together, and united 

 at their joints by keys. The planks in the outer row, which 

 are the thickest, are placed upright or vertically ; those in the 

 inner row are placed horizontally. Between the two rows is inter- 

 posed a species of pasteboard, impregnated with bituminous sub- 

 stances. The joints of the principal pieces, which form the angles 

 of the roofs and floors, are secured by buttons ; the angles of the 

 VOL. II. Nov. 1831. 2 D 



