These small brick sized items where made by one of Lord Caasi’s apprentices to impress a kitchen wench and was quickly capitalized on.
These items look like a copper ingot about the size of a brick, and have a hollow crystal sphere set two thirds of the way down. The sphere is half filled with Philosopher’s Mercury mixed with water, and the brick itself has that sheen giving when alloyed with Philosopher’s Mercury. The top of the item has the symbol for top cut into it, but is otherwise unblemished. The item comes in two parts, the first being the copper brick, and the second being a dark metal box that the brick fits into.
The item repels water up to three feet away in a semi-sphere emitted from the bottom of the brick. The alloy with the metal, and the mixure in the crystal sphere “filter” out all noise ecept the one sound that will make it work right, so no matter where it is, or what all is “hearing” the only time it will stop working is if there is NO noise at all. This allows people to work with it, and it can be placed in the box that comes with it to keep it from working at all. When these items are attached to the inside hull of a ship or boat, it allows the vessel to float on a cushion of air, negating friction with the water, while still allowing the boat men to use oars, poles or sails.