158 



GENERAL SCIENCE 



If the open flame burner is in use on your premises, do not allow 

 the gas to burn from it with a blowing noise and a ragged flame, 



FIG. 129. Dipping. In order to prepare the mantle for subsequent handling 

 and for shipment, it is dipped into a bath of collodion and allowed to dry. 

 Packing. The mantles are then passed to the packer, and packed according 

 to the desire of the consumer. Loop mantles are suspended in paper 

 tubes by cords. Cap mantles are mounted on supports, and the supports 

 securely fastened to the caps. 



as a considerable quantity of gas can be wasted in this way. Regu- 

 late the flow of gas through the burner with the burner key so that 



it burns with a steady, even 

 flame, or use a burner that is 

 self-regulating. 



It is quite necessary that all 

 passages and orifices of gas burners 

 be kept clean and in perfect con- 

 dition to obtain the best results 

 from the gas consumed. 



Experiment with Burner. 

 Light a Bunsen burner. Allow as 

 much air as possible to enter at the 

 base. Note the results. Shut all 

 the air off at the base and explain 

 what happens. Adjust the burner 

 so that a noiseless blue flame is produced. Experiment with a gas 

 stove in the same way. 



FIG. 130. Why are the burners 

 arranged in the shape of a star? 

 Why are the burners in an oven 

 arranged in a row? 



