Egg incubators
do not require a thermostat or temperature gauge because they
mimic mother bird and thus “
one temperature fits all”.
If it is an egg incubator then a small heating element is probably located in the enclosed base of the unit.
Both the 1st & 2nd picture in the 1st post clearly shows that the unit is mounted on the 2 round “slider” bars. And that appears to be a similar knob at the center of the base as is on the door, which is obviously used for “pulling” the unit on said “slider” bars.
In the early days of electrical wiring it was a roll of
single strand insulated wire and
white porcelain insulators, no wrapped multi-wire cables. When home were wired for that new fangled “electric” thingy it was done via what they called
'nob and tube' wiring. In really old homes, barns, etc., one can still find remenants of them being originally wired via that method. I found them when I renovated my 1862 farm house.
See picture of said “tube” below. From source:
http://www.etsy.com/listing/66121111/old-porcelain-insulator-tubes
