should be provided by means of tile drains 

 laid below the sewage tile as shown in 

 Fig. 7. In some cases an impervious 

 stratum underlying the filter earth is un- 

 derlain by a stratum of sand. Cases have 

 been noted in which this impervious 

 stratum has been broken by dynamite at 

 15 to 20-ft. intervals along the tile line, 

 to provide natural drainage. 



If surface disposal is not feasible, as 

 when the soil is compact and nearly im- 

 pervious, or is swampy making underdrain- 

 age hard to arrange, disposal by inter- 

 mittent flow and filtration is necessary. 



The sand filter usually is a bed of sand 

 3 to 4 ft. thick, which is fine on top and 

 gradually increases in size to coarse 

 gravel at the bottom. The sewage from 

 the tank is distributed over the filter by 

 means of tile laid loose-jointed over the 

 surface in much the same manner as in 



The above table is computed on the basis that the inlet and outlet of the 

 settling chamber are placed with inverts twelve inches below the 

 roof, making the sewage depth twelve inches less than the inside depth 



the ground surface distribution system. 

 The filter should be sufficiently porous 

 and there should be sufficient natural or 

 artificial underdrainage to allow every 

 dose of sewage to sink away rapidly. 

 Sewage should not stand on the surface 

 of the filter for any length of time, as this 

 soon destroys its purifying properties. 

 About 45 sq. ft. of filter should be pro- 

 vided for each person served by the sewer. 

 The area should be divided into from three 

 to five beds so that each bed may be al- 

 lowed to rest occasionally. A plan and a 

 partial section of a sand filter for a family 

 of eight persons is shown in Fig. 8. 



In constructing a filter, a sufficient area 

 should be leveled off and small earth 

 embankments be made 18 in. to 2 ft. high 

 to inclose the beds. The depth of the 



filtering material will depend largely on 

 the porosity of the subsurface and the 

 means of underdrainage, but it is well 

 to have it not less than 2 3/^ ft.; 3 to 5 ft. 

 is better, but the depth should not ex- 

 ceed 6 ft. A good plan is to allow a 

 minimum of a cu. yd, of filtering material 

 for every 50 gal. of sewage flow. 



Lighting an Alcohol Lamp with a 

 Glass Rod 



PLACE a quarter of a teaspoonful of per- 

 manganate of potash crystals in the 

 bottom of a glass tumbler, moistening 

 them with a few drops of water. Then, just 

 barely cover the mixture with concentrated 

 sulphuric acid — oil of vitriol. A very vigor- 

 ous action will at once begin, and a glass rod 

 dipped in the mixture, then touched to the 

 wick of an alcohol lamp will immediately 

 create a flame. The 

 chemical action in the 

 tumbler produces 

 ozone, a concentrated 

 form of oxygen, and 

 the rapid oxidation of 

 the alcohol in the 

 wick brings it to its 

 kindling temperature 

 and lights the lamp. 

 A little ether poured 

 on a glass plate can 

 can also be ignited 

 by simply touching 

 it u4th the glass rod 

 after the rod has 

 been dipped in the 



tumbler. This experiment may be used to 

 advantage by the house magician to fill out 

 the program of an evening's entertainment. 



To Prevent Mildew in a Damp 

 Clothes Closet 



THE careful housekeeper is often greatly 

 troubled and perplexed by rust and 

 mildew formations caused by damp closets. 

 This state of affairs can be easily remedied 

 if an earthenware bowl or a deep plate full 

 of quicklime be placed in the closet. The 

 lime absorbs the moisture, sweetening and 

 disinfecting the damp corners. Rodents and 

 insects that are likely to congregate in such 

 places greatly dislike the odor of the lime. 

 When the lime becomes slaked it should be 

 thrown away and a fresh supply substituted. 



