 All right, next question is, how lighting is measured? Now we have so much of light here, how do we measure the amount of light that we get? Usually the light output is measured in luminous flux, or the amount of light falling on horizontal surface. All lamps, for example, this one, is listed with how many lumens? Lumens is the output from a particular bulb. How much light do we get from this bulb? Lumens, not watts. Watts is the second one that you see here, and that is how many watts, or how much power are we drawing from the electrical wires? And the third one that is indicated on every package that you see is the number of hours. In other words, this is the life expected life of this bulb. And you can see here, lumens is the light output. Lumens is an indication of how much light we get from these bulbs. And for example, as I said, 40 watt bulbs give you 500 lumens, and here we have a 60 watt bulb, which gives you 865 lumens. It is not proportional, but as the wattage increases, you get more and more number of lumens.