How to Preserve Eggs

From Houghtalings Handbook ©1887

To each pailful of water, add two pints of fresh slacked lime, and one pint of common salt; mix well. Fill your barrel half full with this fluid, put your eggs down in it any time after June, and they will keep two years if desired.

So, I looked up slacked lime. Here's a link to wikipedia if you'd like to read further. Today slaked lime is called calcium hydroxide and is found in soft drinks.

I decided to find another source and came across "The New Family Receipt-book ©1820 and found these three entries below.

394. To preserve Eggs sound for the space of Two Years,
For the following process, for keeping and preserving eggs perfectly sound, a patent was granted in February, 1791, to Mr. Jayne, of Sheffield, Yorkshire :
Put into a tub or vessel one bushel, Winchester measure, of quicklime, thirty-two ounces of salt, eight ounces of cream of tartar, and mix the same together with as much water as will reduce the composition, or mixture, to that consistence, that it will cause an egg put into it to swim with its top just above the liquid : then put, and keep the eggs therein, which will preserve them perfectly sound for the space of two years at the least.
This method is not the worse for being simple, and the still simpler one of merely keeping eggs in salt, is known by many good housewives to preserve eggs quite sound for a considerable time.
395. Manner of preserving Eggs perfectly fresh, for Twelve Months.
Having provided small casks, like oyster barrels, fill them with fresh laid eggs ; then pour into each cask, the head of which is supposed to have been first taken out, as much cold thick lime-water as will fill up all the void spaces between the eggs, and likewise completely cover them. The thicker the lime-water is the better, provided it will fill up all the interstices, and be liquid at the top of the cask ; this done, lay on the head of the cask lightly. No farther care is necessary, than merely to prevent the lime from growing toe hard, by adding, occasionally, a little common water on the surface, should it seem so disposed, and keeping the casks from heat and frost. The eggs, when taken out for use, are to be washed from the adhering lime with a little cold water, when they will have both the appearance and qualities of fresh laid eggs, the lime preserving them from shrinking or putridity.
396. Manner of preserving Eggs perfectly fresh,
for Twelve Months.
The most simple and easy mode of preserving eggs is to rub the outside of the shell as soon as gathered from the nest, with a little butter, or any other grease that is not fetid. By tilling up the pores of the shell, the evaporation of the liquid part of the egg is prevented ; and either by that means, or by excluding the external air, which Fourcroy supposes destroys the milkiness which most people are fond of in new-laid eggs, that milkiness will be preserved for months, as perfect as when the egg was taken from the nest.