STEAM. 117 



"stream of mist") is the real steam, 

 before it has been condensed by air. 



Q. Why is not ALL the stream INVISIBLE, as 

 well as that half -inch ? 



A. As the steam comes in contact 

 with the colder air, the invisible particles 

 (being condensed^, roll one into another, 

 and look like a thick mist. 



Q. What BECOMES OF the STEAM ? for -it soon 

 vanishes. 



A. After it is condensed into mist, 

 it is dissolved by the air, and dispersed 

 abroad as invisible vapour. 



Q. And what BECOMES of the INVISIBLE 



VAPOUR 



A. Being lighter than air, it ascends 

 to the upper regions, where (being again 

 condensed) it contributes to form clouds. 



Q Why does a METAL SPOON, left in a sauce- 

 pan, RETARD the process of BOILING? 



A. The metal spoon (being an excel- 

 lent conductor) carries off the heat from 

 the water ; and (as heat is carried off by 

 the spoon) the water takes a longer 

 time to boil. 



