The tube shown at 4 is, we think, an improvement upon all of the foregoing, for upon it there is no side tube to break off, and everything is comprised in a small space.

The area of the flue, which is rectangular is 990 square inches, therefore the area is equal to that of a tube 35-1/2 inches in diameter; and such a tube, to have a heating surface of 497 square feet, must be 53.4 feet or 640.8 inches in length.

The chief peculiarity of this type of engine consists in the boiler, which is fitted with a combustion chamber stocked with perforated bricks, the tubes being only 5 ft. 4 in.

The little tubes forming the lateral line are also silvery.

These tubes are wrought iron, firmly screwed into the bends, so as to prevent any possible breaking.

A.The tubes of marine boilers are generally iron tubes, three inches in diameter, and between six and seven feet long; but sometimes brass tubes of similar dimensions are employed.

With an apparatus like the one here figured, and in which the filtering tube is eight inches in length by about one inch in diameter, about four and a half gallons of water per day may be obtained when the pressure is two atmospheresthe mean pressure in Mr. Pasteur's laboratory, where my experiments were made.

Madame Tube, the mother of Madelaine, was a great sufferer from rheumatism.

The slender, trumpet-like tubes immediately became shafts of masonry, and sank deep into the earth; the lip of the flower changed into a circular mouth of rose-colored marble, and the people, leaning over its brink, lowered their pitchers to the bottom with cords, and drew them up again, filled to the brim, and dripping with honey.