HOME HYGIENE. 



359 



arj, determines in great part the healthfulness 

 of the site, and therefore no building-site 

 should be chosen where the ground-water is 

 not stationary at a point lower than the pro- 

 posed foundation of the new house, or where 

 it can not be made so by drainage. 



2. Foundations. All loam should be re- 

 moved, and the bed-stone laid down to the solid 

 earth whenever possible. If the earth be at all 

 damp, a drain-pipe should be laid outside the 

 wall a few inches lower than the bed-stone, and 

 the basement covered with four or five inches 

 of good concrete, upon which the floor may be 

 laid. It is obvious that the drain-pipe should 

 not be laid so near the bed-stone as to affect 

 the security of the wall. If the ground- water 

 still remain in the soil near the concrete, no 

 amount of that material will make a dry cel- 

 lar ; the only remedy in such a case is to lay 

 additional pipes for ventilation which shall be 

 connected with the kitchen or other regularly 

 heated flue. " Damp-proof courses " of im- 

 pervious bricks are frequently used to keep 

 out the external wet from basements, but are 

 practically useless where the moisture rises 

 inside the foundation- walls. 



3. Walls. Impervious bricks should not 

 be used for outside walls, above the ground- 

 courses, for it is quite necessary that transuda- 

 tion of moisture and carbonic oxide should take 

 place from within outward. It is, however, an 

 excellent practice to use impervious bricks for 

 party walls, for precisely the opposite reason. 

 An area should be constructed about the outer 

 wall, of greater or less extent according to the 

 amount of space available, extending down to 

 the level of the bed-stons. A dry-area wall 

 has been recommended where the space is lim- 

 ited, but it is obvious that the "dry" area, 

 which is really an additional wall, is itself ob- 

 jectionable unless ventilated at the top and 

 bottom, and it is therefore clear that the wall 

 would be quite as well without it. In the con- 

 struction of walls the aim should be, not only 

 to exclude the external moisture from the 

 dwelling, but by means of the porosity of the 



FIQ. 1. HOLLOW WALL PROM EASSIE. a, vamped brick ; 

 6, <Z, straight ; c, rafter drip. 



wall to allow the escape of internal moisture. 

 Hollow walls are therefore recommended as 

 fulfilling the necessary conditions. Mr. Eassie 

 (" Sanitary Arrangements for Dwellings,' 1 Lon- 



don, 1874) recommends that the hollow walls 

 be constructed as shown in the cut, with Mr. 

 Jennings's patent bonded bricks. 



4. Heating and Ventilation. It is not known 

 when houses were first artificially heated ; there 

 are, however, numerous legends concerning the 

 discovery of fire, of which one of the best is 

 that given by Vitruvius: "A tempest, on a 

 certain occasion, having exceedingly agitated 

 the trees in a particular spot, the friction be- 

 tween some of the branches caused them to 

 take fire ; this so alarmed those in the neigh- 

 borhood of the occurrence that they took to 

 flight. Returning to the spot after the tempest 

 had subsided, and finding the warmth which 

 had thus been created extremely comfortable, 

 they added fuel to the fire excited, in order to 

 preserve the heat, and then went forth to in- 

 vite others, by signs and gestures, to come and 

 witness the discovery." 



It is doubtful if the present century has added 

 very much to the long list of inventions of heat- 

 ing apparatus proposed by Franklin and Rum- 

 ford, with the exception of the inventions of 

 Gal ton and Morin, although for many years the 

 subject has been faithfully studied. Mr. Pepys 

 informs us under date of February 15, 1664-'65, 

 that he went " with Creed to Gresham College. 

 . . . But it is a most acceptable thing to hear 

 their discourse, and see their experiments; 

 which were this day on fire, and how it goes 

 out in a place where the ayre is exhausted, 

 which they showed by an engine on purpose." 



The subjects of heating and ventilation are 

 perceived, upon reflection, to be intimately con- 

 nected with each other, and are therefore 

 properly treated of at the same time. The 

 methods of heating dwellings, in use in Amer- 

 ica at the present time, consist of open grates 

 or " fireplaces," furnaces, heaters, and stoves. 

 Warm water and steam, although much used 

 in heating public buildings, are but little used 

 for dwellings. Parkes states that heat is com- 

 municated by radiation or convection. Heat is 

 radiant where it is directly emitted from the 

 flame or incandescent substance. Convective 

 heat is that transmitted by the motion of the 

 particles of a heated object. Radiation is ac- 

 complished by means of open fires, and convec- 

 tion by the various patterns of stoves and heated 

 pipes. The open fire is at the same time the 

 most pleasant to the eye, and that most health- 

 ful of all methods now in use. Its superiority 

 in a sanitary point of view arises from the fact 

 that the open fire is one of the best-known 

 means of ventilation, and at the same time it is 

 admitted that radiant heat is more beneficial in 

 its effects upon the human body than the con- 

 vective. The success of an open fire depends 

 largely upon the care with which the grate and 

 chimney have been constructed. The grate 

 may be, and usually is, dispensed with, where 

 wood is burned in the large fireplaces. There 

 is great diversity in the relative velocity of 

 air-currents in different chimneys, out of pro- 

 portion to any apparent difference in their 



