For most people, storing eggs is no more problematic than finding sufficient space in the refrigerator. But if you live on a remote and isolated homestead, or somewhere that doesn't inspire confidence in its ability to provide reliable electric power, or if you are prone to sudden cravings for eggs in large quantities, you may need a reliable alternative type of storage. In such cases, knowing that your ancestors stored surplus eggs in ash, for example, may prove to be more valuable than your friends and co-workers would have you believe.

The Rural Efficiency Guide¹ says:

Use one gallon of water-glass (sodium silicate) to nine or ten gallons of water. Boil the water, add the water-glass, and mix the solution thoroughly. Then you just immerse the eggs in it. Eggs preserved by this method will keep at least a year in good condition.

They also suggest preserving eggs in a solution of limewater², and they also recommend that eggs 'May also be preserved for several months by packing them in dry salt'. Further, they note, 'In cold places like Alaska they preserve eggs by simply packing them in rolled oats'.

Another old farming book recommends melting lard, dropping the eggs in, and letting it set again, for long-term storage.

Turning to a more modern reference, A Guide To Raising Chickens³ has this table for how long eggs keep:

Thermostabilization involves heating to 160°F for ten minutes. You can also combine thermostabilization and oiling, which doesn't extend the shelf life but does make them cook a bit better in the end.