Answer:
What can be measured but not seen?
Iron roof, glass walls, burns and burns and never falls.
When it is alive we sing, when it is dead we clap our hands. What is it?
We are few to the wise; We are abundant to the drunken; We can calm the beast and are precious to the child; We can devour the heart, without piercing the skin
No matter how little or how much you use me, you change me every month.
If it’s information you seek, come and see me. If it’s pairs of letters you need, I have consecutively three. What am I?