You found a white bird egg on the ground not in a nest and you took it home what should you do?

Well, I found four chicken eggs on the ground once, I took them home and put them in a blanket with a hot water bottle. I didn't have an incubator so I warmed them, changing the water every now and then, If the egg is unrecognisable then maybe you should just keep it warm until it hatches, then feed it formula until it can eat seed. My eggs didn't hatch but maybe yours has some hope. I hope I helped.