Egg shells as moulds, containers (scented 'bombs'of rosewater; maple sugar; garden pot), clarifier (coffee, soup, jelly), designs

Egg shells filled with blanc mange

Hen's Nest in Jelly.
FILL some egg moulds with blanc mange, and when they are cold, turn them out; but if you have no moulds, break holes in the thick ends of six or seven eggs,and pour out the yolks and whites as clear as you can. Set them on one end in salt, and with a funnel fill them with strong blanc mange.
When they are cold, very carefully break the shells, and take them off the blanc mange. Put a little jelly at the bottom of a round mould, or China bowl. Lay the eggs on it, and put on a little jelly to fix them to their places. When it is cold, put in more jelly blood-warm, till it is even with the eggs.
Then lay some vermicelli over and round them, to make it look like a nest. When it is cold, fill the mould or bowl quite full, fet it aside all night, the next day turn it out intoa dish, and garnish with flowers, sweetmeats, or what you please.
Collingwood, Francis. The Universal Cook. 1792/1806 [also Raffald 1769]

Scented Egg shell 'bombs'

...egg-shells full of sweet water, you may by a great Pin take all the meat out of the egg by blowing, and then fill it up with the rose-water...
This done to sweeten the stink of powder, let the Ladies take the egg-shells full of sweet waters and throw them at each other.
Triumphs & Trophies ... Twelfth-day
The Accomplisht Cook by Robert May.  1685

Egg-Shell Garden. St Nicholas. 1904 sketch
Thumb pots or Egg shells. American Primary Teacher. Boston 1877
Seeds in egg-shells. Arthur's Home Magazine. 1884
On the preservation of Egg-shells for cabinets of Natural History. Essays on Natural History. 1844

Easter Eggs links list
Engraved Egg Shells. The Girl's Own Book. Lydia Child. 1853
Filled with maple-sugar. On the Wing. 1868

Clearing coffee. Domestic cookery. Elizabeth Lea. 1859
Fining or clarification. Jelly. Johnson's New Universal Cyclopaedia. 1876
Clarify soups. Buckmaster's Cookery. 1874