METHODS OF RESEARCH: APPARATUS 89 



One simple piece, a sort of tall deep cupboard, which any car- 

 penter can make and which takes up very little room, will 

 sterilize 6 bushels of soil in an hour (Fig. 57) . This earth is 

 held in half-bushel lots resting on sacking in shallow drawers 

 having wire-mesh bottoms. The steam enters at the bottom 

 (back) and the air flows out at the top (front) through openings 

 which are closed by a slide w T hen steam begins to escape. The 

 cupboard is 3 inches deeper than the length of the drawers and 

 every other one of these is shoved back so that the steam (15 

 pounds pressure) readily passes under and over each drawer. 

 The later are 18 inches wide, 30 inches long and 3 inches deep. 



The other pieces of hothouse apparatus required are very 

 simple. 



In addition to knives, labels, steel needles, hypodermic 

 syringes (rarely necessary) and atomizing devices (a cologne 

 sprayer will do), I need mention only alcohol lamps, cages with 

 walls of glass (inoculation cages) and cages with walls of wire- 

 gauze (insect cages). These may be made of such size as will 

 suit the best convenience of the experimenter. One whole 

 side should be used as an opening (double door), and for the 

 insect cages an additional small opening is very desirable. The 

 bottom of each is, of course, open, resting on the earth, or on a 

 bench or platform of some sort. 



5. For the Photographic Room 



If possible, the photographic room should have north, 

 south, and overhead light, or at least south light and overhead 

 north light in order that advantage may be taken of direct 

 sunlight for heliostats, etc., and overhead light for a variety 

 of indoor photographic lightings. For these reasons it is best 

 located on a top floor. Our own rooms being on a middle floor 

 we have had to make shift with south light only, taking it from 



and are shorter than the depth of the chamber by a few inches allowing every other 

 one to be shoved back or pulled forward so that steam, which enters at the back, 

 at the bottom, may circulate freely around each one. The soil is placed on coarse 

 sacking and each drawer holds a half bushel. Air is displaced through the two 

 holes at the top and these are closed by slides when steam begins to appear. Photo- 

 graph from Dr. B. T. Galloway. 



