how can one hatch a chick in absence of the hen?

Question: how can one hatch a chick in absence of the hen?
- Keywords:
  chicken
Asked by abjb256 to Susan, Steven, Rose, Rita, Alex on 27 Jan 2017.
- Rose Kigathi answered on 27 Jan 2017:
  
  By using heat to keep fertilised eggs warm. This is done by many farmers. It is using “incubation machines”. The egg must be fertilized for each to hatch.
- Steven Adala answered on 28 Jan 2017:
  
  Nowadays incubators can be bought for this purpose. The most common ones are the electric incubators but new ones in the market can use solar energy to hatch eggs. The average period for eggs to hatch in an incubator is 21 days. They are easy to use an come with instructions on how to use them.

Question: how can one hatch a chick in absence of the hen?