cnr steam locomotives

This picture amazingly captures the think layer of clouds in the valley at the south of Lake Como, northern Italy. In the above image, the dense cloud hides almost the valley and instead gives off some artificial lights which make town such as an opaque blanket. The village over distance is clearly seen out from the blanket. The black exhaust Black is apparently a depressing color. The reason ought to be rich mixture. That is to say, the mixture of gas in cylinder component is at night normal level. The incomplete combustion gas inside the combustion chamber make the carbon particle exhausted with the waste gas. Failure probably will come from the following reason: