be crowded out, is the hardest of all. * * * * * HIGH SPEED ENGINE AND DYNAMO. We illustrate a high speed engine and dynamo constructed by Easton & Anderson, London. This plant was used at the Royal Agricultural Society's show at Doncaster in testing the machinery in the dairy, and constituted a distinct innovation, as well as an improvement, on the appliances previously employed for the purpose. The separator, or whatever might be the machine under trial, was driven by an electric motor fed by a current from the dynamo we illustrate. A record was made of the volts and amperes used, and from this the power expended was deduced, the motor having been previously carefully calibrated by means of a brake. So delicate was the test that the observers could detect the presence of a warm bearing in the separator from the change in the readings of the ammeter. [Illustration: IMPROVED HIGH SPEED ENGINE AND DYNAMO.] The engine is carefully balanced to enable it to run at the very high speed of 500 revolutions per minute. The cranks are opposite each other, and the moving parts connected with the two pistons are of the same weight. The result is complete absence of vibration, and exceedingly quiet running. Very liberal lubricating arrangements are fitted to provide for long runs, while uniformity of speed is provided for by a Pickering governor. The high pressure cylinder is 4 in. in diameter, and the low pressure cylinder is 7 in. in diameter. The stroke in each case is 4 in. [Illustration: Fig. 2.] The dynamo is designed to feed sixty lamps of 16 candle power each, the current being 60 amperes at 50 volts. The armature is of the drum type. The peculiar feature of it is that grooves are planed in the laminated core from end to end, and in these grooves the conductors, which are of ribbon section, are laid. Slips of insulating material are laid between the coils and the dovetailed mouths of the grooves are closed with bone or vulcanized fiber, or other dielectric. At each end of the core there are fitted non-magnetic covers. At the commutator end the cover is like a truncated cone, and incloses the connections completely. One end of the cone is supported on the end plate of the armature and the other end on a ring on the commutator. A bell-shaped cover incloses the conductors at the other end of the armature. The result is that the conductors are completely incased, protected from all mechanical injury, and positively driven. They can neither be displaced nor abraded. The conductors on the magnet coils are likewise carefully protected from harm by metal coverings. These dynamos are made in sixteen sizes, of which seven sizes are designed to feed more than 100 lamps, the largest serving for 600 lamps. [Illustration: Fig. 3.] Messrs. Easton & Anderson are showing machinery of this type at the Crystal Palace Electrical Exhibition now open in London.--_Engineering_. * * * * *