Re: what were used before mirrors were invented?

Before modern mirrors, people could either use their reflection in pools of 
water, or see their reflection in polished metal. Obviously, the image in a 
pool of water can involve distortions from ripples and also some loss of 
clarity because not all of the light is reflected back: some is transmitted 
into the depths of the water and scattered or absorbed.

You can read more about the history of mirrors at these websites:

A brief history of mirrors


http://nl.ijs.si/~damjan/glass.html