The clay slab, which crumbled during its recovery and is now entirely lost, sat on a one inch layer of sand, placed in a rectangular pit.

On top of this was a 36 inch layer of topsoil into which the planting was made.

But the shorter piece of flooring covered with the three-quarter inch layer of fireproofing - equivalent to what was in the towers when they were completed - did last the two hours.

Subsequent investigation found a six inch layer of sediment in the bottom of the pipe section.

The floor was covered with an inch layer of grease and packed debris.

Therefore in the aquarium incorporate a 1 -2 inch layer of dried clay or clay granules.

If you have an open fire you should keep the grate filled with a 3 to 4 inch layer of fuel and regulate the burning rate by carefully using the air control at the front of the grate.

It inhabits the top 1/2 inch layer of soil.

The hull of the 'Dolphin' was planked with four inch thick mahogany covered by a two inch layer of teak, then sheathed with heavy gauge copper.

The thin 10-20 thousandths of an inch layer of protective lacquer is equivalent.