Answer:
Until I am measured I am not known, Yet how you miss me when I have flown.
My second is performed by my first, and it is thought a thief by the marks of my whole might be caught.
Two brothers we are, great burdens we bear. All day we are bitterly pressed. Yet this I will say, we are full all the day, and empty when go to rest.
Whilst I was engaged in sitting. I spied the dead carrying the living
Voiceless it cries, Wingless flutters, Toothless bites, Mouthless mutters. What is it?
They are many and one, they wave and they drum, Used to cover a state, they go with you everywhere.