It was a vertical water-tube boiler, constructed from four concentric tubes.

J is the polar moment of inertia, for a round shaft or concentric tube only.

In appearance, it was a slender metal cylinder, two feet long, with an inner concentric tube projecting at each end.

In the Frasch process, three concentric tubes are introduced into the sulfur deposit.

The tubes are closed at one end, and they contain a concentric inner tube.

The resulting gas is then burnt by heated secondary air coming up a concentric tube.

It is identical to the second moment of area J for concentric circular tube, or round solid shafts only.

In some cases concentric tubes form, one inside another.

Inside each column were three concentric tubes.

Inside the concentric tubes of these layers is mesenchyme, a kind of connective tissue.