Robert West in upstate New York writes:
I dislike the mess of humidifiers, so in the winter I put out a bowl of water to evaporate, which helps a little. If I put out another bowl of water on the other side of the room, will I double the amount of water evaporating, or will the total remain the same?
More water is better. To increase the effect, place the bowls on or near heat sources. Also, shallow pans work better than bowls.