less proportion of moisture. The vapor was condensed previous to final
expansion and abstracted as water in the drying apparatus. The machine
was exhibited at work in connection with a cold chamber which was
kept at a temperature of about 10 deg. Fah., besides which several
hundredweight of ice were made in the few days during which the
experiments lasted. This machine is in all respects an improvement on
the machine which we have already illustrated. In that machine Messrs.
Hall were trammeled by being compelled to work to the plans of others.
In the present case the machine has been designed by Mr. Lightfoot, and
appears to leave little to be desired. It is a new thing that a cold air
machine may be run at any speed from 32 to 120 revolutions per minute.
In its action it is perfectly steady, and the cold air chamber is kept
entirely clear of snow. The dimensions of the machine are also eminently
favorable to its use on board ship.-_The Engineer_.

[Illustration: DRY AIR REFRIGERATING MACHINE]

* * * * *




THOMAS'S IMPROVED STEAM WHEEL.


The rotary or steam wheel, the invention of J.E. Thomas, of Carlinville,
Ill., shown in the annexed figure, consists of a wheel with an iron rim
inclosed within a casing or jacket from which nothing protrudes except
the axle which carries the driving pulley, and the grooved distributing
disk. Within this jacket, which need not necessarily be steam-tight,