I would use a 12/3 cord especially if your going 50ft or more from the outlet.
marking qauge?
Gauge is a measure of how large the opening of the needle is. The larger the number the smaller the hole. Most venipuncture is done with a 16-24 gauge needle, depending on the size of the patient and the location of the vein. A 10 gauge needle would be huge.
There are instruments called Ceilometers which can measure cloud height and cover, but they're not especially accurate for cover (they are quite good for cloud height, especially at night) as a cloud can sit over the instrument and give a false reading. Also, unless cloud passes over them they give a false negative. The best instrument for measuring cloud cover is a trained Mark I eyeball (or two)Read more: What_instrument_is_used_to_measure_clouds