Chauvière's propagating-frame, an apparatus used by the French, is shown in Fig. 37. It is essentially a miniature greenhouse. The sashes are seen at _c c_, and above them is a cloth or matting screen. The sides below the sashes are enclosed, preferably with glass. The bottom or floor is moveable, and it is sometimes divided into two or three sections to allow for the accommodation of plants of different sizes and requirements. These sections are raised or lowered and are held by pegs. At a is shown a section of floor elevated, and at the left another section occupying a lower position. Heat is supplied usually by hot water in the tubes, _d d_. A very elaborate circular French device, known as Lecoq's propagating-oven, is illustrated in Fig. 38. It is an interesting apparatus, and is worth attention as showing the care which has been taken to control the conditions of vegetation and germination. It is too elaborate for common purposes, and yet for the growing of certain rare or difficult subjects it might find favor among those who like to experiment; and it affords an accurate means of studying plant growth under control. The apparatus is sold in France for about $6. All the portion below the glass top, _P p_, is made of earthenware. The base, _a a_, holds a lamp, _d_; _e_ is a water reservoir to which water is supplied by means of the funnel, _j_. A vase or rim, _b b_, rests upon the base, and upon it a plate or disc, _c c_, is fitted. Above this is a glass top, _P p_. Air is admitted to the apparatus at _i_, _K K_, and between the vase and plate, as at _c_ on the right. The plate contains two circular grooves, _g g_ and _h h_. In these grooves the soil is placed or pots plunged. The heat circulates in the valleys _m_ and _n n n n_, and supplies a uniform temperature to both sides of the plants. [Illustration: Fig. 37. Chauvière's Propagating-oven.] [Illustration: Fig. 38. Lecoq's Propagating-oven.] [Illustration: Fig. 39. Barnard's Propagating-tank.]