COMBUSTION AND OXIDATION 81 



30. Large oil lamps and oil heaters have a circular burner with an 

 opening in the center through which air circulates. Of what advantage 

 is this? 



31. Why does blowing or fanning a fire make it burn faster? 



32. Try heating a glass rod or piece of wire, first in the tip of the blue 

 flame and then in the orange flame. Which is the hotter? 



33. Does the 'hotter flame use more gas? If not, how do you account 

 for the heat? 



FIG. 28. Effect of wire gauze on flame. (Jones.) 



34. All gas ranges are constructed on the principle of the bunsen 

 burner. Examine such a range and locate the opening through which 

 air is admitted to the burner. 



35. Should the flame of the gas range be blue, or orange-colored? 



36. Light the bunsen burner and press a piece of wire gauze down on 

 the flame. Does the flame pass through the gauze? 



37. Place a piece of wire gauze on the bunsen burner in such a way 

 that the gas will rise through it. Turn on and light the gas above the 

 gauze. Then slowly lift the gauze up from the burner. Does the flame 

 pass through the gauze? 



