APPENDIX, 



APPARATUS FOR EXPERIMENTS. 



For the assistance of lecturers, teachers, and home students, the fol- 

 lowing list is given of cheap and simple apparatus and materials for 

 performing most of the experiments described in this work. These 

 experiments, although simple, exhibit principles of much practical im- 

 portance. A few articles of a more costly character are given in a 

 second list. 



1. Inertia apparatus, p. 23. The concave post or stand is sufficient, 

 the snapping being done by the finger, although a spring-snap performs 

 the experiment more perfectly. 



2. Weight with two hooks and fine thread, p. 23. 



3. The inertia of falling bodies may be simply shown, and the pile- 

 engine illustrated, by placing a large wooden peg or rod upright in a 

 box of sand, and then dropping a weight upon its head at different 

 heights, which will drive the rod into the sand more or less, according 

 to the distance passed through by the falling weight. 



4. A straw-cutter, so made that the fly-wheel can be easily taken off, 

 will show in a very striking manner the efficacy of this regulator of 

 force. 



5. Two lead musket balls will exhibit the experiment in cohesion, 

 p. 42. Balls or lead weights with hooks may be separated by sus- 

 pending weights to show the amount of force required to draw them 

 asunder. Metallic buttons or plates an inch in diameter, with hooks, 

 vi'ill show the great strength needed to separate them when coated 

 with grease, p. 42. 



6. Capillary tubes of different sizes, two straight small panes of glass, 

 and a vessel of water, highly colored with cochineal or other dye, to 

 exhibit capillary attraction. 



7. Glass tube, piece of bladder, and alcohol, for experunent described 

 on p. 49. 



8. The cylinder for rolling up the inclined plane, represented by 



