GROTTO (from the French, grotte) is used for a little artificial edifice made in a garden, in imitation of a natural grotto.
The outsides of these grottos are usually adorned with rustic architecture, and their inside with shell-work, fossils, &c. finished likewise with jets d'eau, or fountains, &e.
A cement for artificial grottos may be made thus; take two parts of white rosin, melt it clear, and add to it four parts of bees' wax ; when melted together, add two or three parts of the powder of the stone you design to eement, or so much as will give the cement the colour of the stone ; to this add one part of flour of sulphur ; incorporate all together over a gentle fire, and afterwards knead them with the hands in warm water. With this cement, the stones, shells, &c., after being well dried before the fire, may be cemented.
Artificial red cora] branches, for the embellishment of grot tos, may be made in the following manner : take clear rosin, dissolve it in a brass pan ; to every ounce of which add two drains of the finest vermilion ; when you have stirred them well together, and have chosen your twigs and branches, peeled and dried, take a pencil, and paint the branches all over whilst the composition is warm : afterwards shape them in imitation of natural cora]. This done, hold the branches over
a (retitle coal fire, till all is smooth and even as if polished.
In the same manner white coral may be prepared with white lead, and black coral with lamp-black. A grotto may be built, with little expense, of glass, cinders, pebbles, pieces of large flint, shells, moss, stones, counterfeit coral, pieces of chalk, &c., all bound or cemented together with the above described cement.
The grotto at. Versailles is an excellent piece of building. Solomon de Cans has :In express treatise of' grottos and fountains.