MECHANICS AND USEFUL ARTS. 37 



operation is completed. By means of this apparatus, engravings may 

 be enlarged or diminished to any necessary extent from the same 

 original. 



Agricultural Implements. The display of different devices for 

 steam-ploughing was very extensive, but embraced no construction 

 of novelty. Many styles of the agricultural locomotive engines which 

 have come into extensive use in Great Britain were shown, each 

 being applicable to the various uses of steam in farm-work, as thresh- 

 ing, chafl-cutting, etc. Each engine is constructed to transport itself 

 and its apparatus from one farm to another, and in neighborhoods 

 where the roads are good they succeed well. A very cheap sta- 

 tionary cast-iron boiler for farm or conservatory purposes, where 

 only fifteen or twenty pounds pressure is required, was deemed wor- 

 thy of a first-class medal. The boiler was tubular, and cast all in 

 one piece ; the exhibitors claiming that this plan of construction 

 effectually prevented breakage and leakage by expansion and con- 

 traction. There were also exhibited iron stalls for horses, admirable 

 for fitness of design and completeness of finish. The rack, manger, 

 and water basin are all of iron, the manger and basin lined with 

 white porcelain enamel. The floors are of brick, or wood, or grooved 

 iron, as preferred, but each is provided with a perforated iron gutter. 

 Wood is preferred for the partition walls, as iron has been some- 

 times broken by a kick, to the damage of the kicker. Halter-straps 

 weighted so as to prevent all possible entanglement, and zinc rollers 

 at the edge of the manger to prevent crib-biting, were accompani- 

 ments of these stalls. A patent safety-spring, to prevent horses from 

 running away, exhibited, consisted of an elastic India-rubber strap, 

 about a foot long, one end being attached to a common straight bit, 

 the other buckled to the riding or driving rein, which is attached to 

 a curb bit. The point of junction is so adjusted that ordinarily the 

 horse will feel only the small bit, whereas, in case of sudden restive- 

 ness, a heavier pull on the rein brings the curb to bear. This simple 

 contrivance may be applied to any riding or driving bridle, and for 

 tender-mouthed horses who will not bear the curb, but still like to 

 run away occasionally, it is invaluable. 



A Danish Milk Pan, for large dairies, which was honored with a 

 medal, was of iron, lined with white porcelain enamel; the dimen- 

 sions six feet by two and a half feet. It was so arranged that one 

 end may be easily raised to pour out the milk as desired. The cream 

 is removed by means of a long-handled skimmer, a light strip of 

 wood between two wheels, adjusted to travel down the edges of the 

 pan, pushing the cream before it into a reservoir stationed at the end 

 to receive it. This reservoir is placed on wheels, and may, if the 

 row of pans is long, have a railway of its own to travel over. A 

 Swedish pan, of tin, provided with a perforated tube through which 

 the milk is allowed to pass out, leaving the cream in the bottom of 

 the pan, was also awarded a medal. 



Bricks and Tiles. An English hand machine for making tiles for 

 drainage, and hollow brick for building purposes, received a medal in 

 this class, as an implement adapted for the use of farmers. A man 

 and two boys, it was stated, could make with it 7,000 tiles of 2|-inch 

 bore and 13 inches long, or 3,000 hollow brick, per diem. The price 

 4 



