210 THE POPULAR SCIENCE MONTHLY. 



When it is to be set up, the three trucks, the length of which 

 is equal to the width of the building, are brought up so as to be 

 parallel in line and a few metres distant from one another, and 

 are arranged so that their floors, which are to form part of the 

 floor of the building, shall be on a level. Light T-shaped joists 

 of iron are stretched across the intervals, supported by trestles 

 when necessary, to receive the paper panels completing the floor. 

 The other details of the structure are substantially as described 

 by M. Ratoin. The interior of this building is entirely satisfac- 

 tory, without visible framework, and without posts to interfere 

 with the arrangement of the beds or with the circulation of the 

 air. The walls, and the ceiling, which is inclined according to the 

 inclination of the roof, are closely jointed and varnished, and 

 consequently easy to wash and disinfect. The only open joints 

 are the vertical couplings, which can be inspected and cleansed by 

 simply taking them apart. The windows are of wire gauze cov- 

 ered with a transparent coating so as to avoid the inconveniences 

 of glass. Ventilation is effected through holes bored at the angle 

 of the ceiling and the wall. — Ed. P. S. M.] 



"We do not purpose here to review all the new applications that 

 have been made of paper, but have intended only to take notice 

 of some of the principal ones, and to call attention to some of the 

 improvements that have been made in them. To the other uses — 

 in wagon-wheels, barrels, horseshoes, etc., mentioned in the begin- 

 ning of this article — we may add a notice of the experiments that 

 have been made in the use of paper in the manufacture of some 

 articles of furniture, such as tables and folding chairs, the princi- 

 pal advantages of which evidently lie in their lightness. These 

 experiments have been timid enough ; but no long time will elapse 

 before paper, which already has its masons and its carpenters, 

 shall also have its cabinet-makers. — Translated for The Popular 

 Science Monthly from La Nature. 



Recent analyses of the air of larger towns, made by a committee of the Brit- 

 ish Association for the Advancement of Science, and reported by Mr. G. A. 

 Bailey, show: 1. That in clear, breezy weather the amount of sulphurous acid is 

 less than one milligramme per one hundred cubic feet of air. 2. That in anti- 

 cyclonic periods it rises very considerably, and in times of fog, maxima of thirty- 

 four and fifty milligrammes have been recorded for the worst districts of Man- 

 chester and London respectively. 3. That wherever an open space or a less 

 densely populated area occurs there is a very marked diminution in the amount 

 of impurities in the air. 4. That an increase in the amount of sulphurous acid is 

 accompanied by at least as large an increase in the amount of organic impurities 

 in the air. 5. That smoke, promoting as it does the formation of fog, and pre- 

 venting free diffusion into the upper stratum of the air, must be regarded as the 

 principal cause of the impure state of the atmosphere in large towns. 



