Day 27, I went and had a look whilst Jemima out feeding. I saw a shattered hole in the side (about half an inch) of one of the eggshells and saw a little pink duckbill inside!!!
Try a small styrofoam cooler perhaps or some kind of a box that has a bit of insulation to keep the heat and humidity in. Put a light bulb in it. Like a gooseneck desk lamp maybe so it's not touching the styrofoam. We don't want a meltdown or fire. I only say styrofoam because it's a good insulator. You could probably use a box or regular igloo cooler too.
Put a little bowl of water in the box/cooler to get the humidity up. the more surface area of the water bowl the better. It's not the deepness of the water it's the surface area that makes the most humidity. It should be at 70% if you've got a humidity gauge.
You'll have to cover the box/cooler with something to keep the heat and humidity inside. Maybe some plastic but it still has to have ventilation?
Keep a close eye on it because you don't want the duckling to hatch while your asleep and then drown in the humidity bowl of water. I never leave my ducklings in the incubator long after they hatch. As soon as they are separated from the shell completely I put them in the brooder.
It will be alone so have a mirror and maybe a little stuffed animal for it to cuddle with so it won't be lonely. Best of luck!
After speaking to my father who hatched lots of chicken eggs in his day, he has told me to put the egg back in the nest, so I have and Jemima went straight pack in, she tapped the egg a couple of times and then shuffled about a bit and settled down. Bit worried about why she pecked the egg, but I think egg is in the best place. What a night I have had!
I have just checked the egg. It is about 12 hours post external pip and duckling has pierced the membrane directly under the shell, so there is a tiny whole there now.