. Annual report of the Agricultural Experiment Station. Cornell University. Agricultural Experiment Station; Agriculture -- New York (State). lO at the top.) Place a couple of pencils beside the relighted can- dle and on them the chimney, as in Fig. i6. Qnes. What is the difference between the way in which the candle burns now and before the chimney was placed over it ? Alls. It flickers, or dances about more. Ques. What makes boys and girls feel like dancing about when thev o"o out from a warm school room ? Ans. The fresh air. Qties. What makes the flame dance or flicker when the chimney
. Annual report of the Agricultural Experiment Station. Cornell University. Agricultural Experiment Station; Agriculture -- New York (State). lO at the top.) Place a couple of pencils beside the relighted can- dle and on them the chimney, as in Fig. i6. Qnes. What is the difference between the way in which the candle burns now and before the chimney was placed over it ? Alls. It flickers, or dances about more. Ques. What makes boys and girls feel like dancing about when thev o"o out from a warm school room ? Ans. The fresh air. Qties. What makes the flame dance or flicker when the chimney is raised by the pencils ? Ans. Because it P'ets fresh air under the chimney. Repeat the first experiment, in which the flame grows gradually smaller till it is extinguished. Qiies. Why now does the flame die out? Ans. Because it had no fresh air. Qiies. Is it really necessary to have fresh air in order to keep a flame burning? Ans. Yes ; since otherwise the can- dle would continue to burn until it is all used up. To prove this further, let the candle be relighted. Place the chimney over it, now having the top completely closed by a i6. supplying air underneath the chimney. piece of paper. Have ready a lighted splinter or match, and. piece of white crockery or window glass, a piece of fine wire about six inches long, a bit of quicklime about half the size of an egg, and some matches. All of these, with the possible exception of the quicklime, can be obtained in any household. If you perform the experiment requiring the lime, be sure that you start with a fresh piece of quick or stone lime, which can be had of any lime or cement dealer. Dur- ing the performance of the following simple experiments, ask your pupils to describe to you what they see you do at each step. The questions inserted in the text are ofTcred merely as suggestions in the developing of the desired ideas. The answers, which are intended only for the teacher, are those which it is desired shall be given by the
Size: 1349px × 1852px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1800, bookcollectionbiodiversity, bookdecade1880
