362 NATURE-STUDY REVIEW [13:8— Nov., 1917 



The Submarines in Our Brook ' 

 This should be an account of the fish, crayfish, and insect larvae, which 

 live below the surface of the water. 



Experiment in Sedimentation 

 Take a glass fruit jar nearly full of water from the brook, add gravel and 

 small stones from the bed of the brook, sand from its borders and mud from 

 its quiet pools. Have it brought into the schoolroom, and shake it thoroughly. 

 Then place in a window and ask the pupils to observe the following things : 



(a) Does the mud begin to settle while the water is in motion; that is, 

 while it is being shaken? 



(b) As soon as it is quiet, does the settling process begin? 



(c) Which settles first — the pebbles, the sand or the mud? Which settles 

 on top — that is, which settles last? 



(d) Notice that as long as the water is in the least roily, it means that the 

 soil in it has not all settled ; if the water is disturbed even a little it becomes 

 roily again, which means that as soon as the water is in motion it takes up 

 its load. 



A Game to Play While Studying the Brook 

 The following game used as a part of the Rhode Island Arbor Day program 

 is so full of excellent suggestions for pupils studying a brook that we publish 

 them as a part of this work. The first six questions can be changed to fit 

 the locality under observation. 



questions for field observations 

 Inter-class Meet, Lincoln Woods, Arbor Day, May n, 191 7 

 Designed for those not assigned to special games, who should organize by 

 classes. The number of points made will depend to some extent upon tbe 

 organization. Each question answered correctly means the credit of one point 

 toward a final score. One delegate from each class should be prepared to 

 report the data agreed upon to the following committee: Dr. Carroll, Mr. 

 Brown, Mr. Vinal. 



1. Which is higher above sea-level, Olney Pond or the next pond in an 

 easterly direction? 



2. Where is North? (Show by sun.) 



3. How far is it by the shortest route from Twin Rock to the Butterfly- 

 Factory? 



4. Point to Providence, Pawtucket and Woonsocket. 



5. Is Olney Pond at its highest level? What is basis for answer? 



6. Account for the difference in soil on the bottom of Olney Pond and on 

 the bottom of the outlet? 



7. Name one floating plant that you may observe in Olney Pond. 



8. Obtain one wading plant. 



9. Obtain one submerged plant. 



10. Catch a dragonfly nymph. 



1 1 . Find the larva of the caddis-fly in its case. 



