pipe.—Annales des Travaux Publics.

MACHINE FOR GRINDING LITHOGRAPHIC INKS AND COLORS.

The grinding of the inks and colors that are employed in lithographing is a long and delicate operation, which it has scarcely been possible up to the present time to perform satisfactorily otherwise than by hand, because of the perfect mixture that it is necessary to obtain in the materials employed.

Per contra, this manual work, while it has the advantage of giving a very homogeneous product, offers the inconvenience of taking a long time and being costly. The Alauzet machine, shown in the accompanying cut, is designed to perform this work mechanically.

ALAUZET'S MACHINE FOR GRINDING LITHOGRAPHIC INKS.

The apparatus consists of a flat, cast iron, rectangular frame, resting upon a wooden base which forms a closet. In a longitudinal direction there is mounted on the machine a rectangular guide, along which travel two iron slides in the shape of a reversed U, which make part of two smaller carriers that are loaded with weights, and to which are fixed cast-steel mullers.

At the center of the frame there is fixed a support which carries a train of gear wheels which is set in motion by a pulley and belt. These wheels serve to communicate a backward and forward motion, longitudinally, to the mullers through the intermedium of a winch, and a backward and forward motion transversely to two granite tables on which is placed the ink or color to be ground. This last-named motion is effected by means of a bevel pinion which is keyed to the same axle as the large gear wheel, and which actuates a heart wheel—this latter being adjusted in a horizontal frame which is itself connected to the cast iron plate into which the tables are set.

This machine, which is 2 meters in length by 1 meter in width, requires a one-third horse power to actuate it. It weighs altogether about 800 kilogrammes.—Annales Industrielles.

A NEW EVAPORATING APPARATUS.

At a recent meeting of the Société Industrielle of Elbeuf, Mr. L. Quidet described an apparatus that he had, with the aid of Mr. Perré, invented for evaporating juices.

In this new apparatus a happy application is made of those pipes with radiating disks that have for some time been advantageously employed for heating purposes. In addition to this it is so constructed as to give the best of results as regards evaporation, thanks to the lengthy travel that the current of steam makes in it.

PERRE & QUIDET'S EVAPORATING APPARATUS.

It may be seen from an examination of the annexed cuts, the apparatus consists essentially of a cylindrical reservoir, in the interior of which revolves a system formed of seven pipes, with radiating disks, affixed to plate iron disks, EE. The reservoir is mounted upon a cast-iron frame, and is provided at its lower part with a cock, B, which permits of the liquid being drawn off when it has been sufficiently concentrated. It is surmounted with a cover, which is bolted to lateral flanges, so that the two parts as a whole constitute a complete cylinder. This shape, however, is not essential, and the inventors reserve the right of giving it the arrangement that may be best adapted to the application that is to be made of it.

In the center of the apparatus there is a conduit whose diameter is greater than that of the pipes provided with radiators, and which serves to cross-brace the two ends, EE, which latter consist of iron boxes cast in a piece with the hollow shaft of the rotary system.

The steam enters through the pipe, F, traverses the first evaporating pipe, then the second, then the third, and so on, and continues to circulate in this manner till it finally reaches the last one, which communicates with the exit, G.

Motion is transmitted to the evaporator by a gearing, H, which is keyed on the shaft, and is actuated by a pinion, L, connected with an intermediate shaft which is provided with fast and loose pulleys.

The apparatus is very efficient in its action, and this is due, in the first place, to the use of radiators, which greatly increase the heating surface, and second, to the motion communicated to the evaporating parts. In fact, each of the pipes, on issuing from the liquid to be concentrated, carries upon its entire surface a pellicle which evaporates immediately.

The arrangement devised by Messrs. Perré and Quidet realizes, then, the best theoretic conditions for this sort of work, to wit:

/l 1. A large evaporating surface. 2. A very slight thickness of liquid. 3. A constant temperature of about from 100° to 120°, according to the internal pressure of the steam. l/

Owing to such advantages, this apparatus will find an application in numerous industries, and will render them many services.—Revue Industrielle.

"FLYING."

To the Editor of the Scientific American:

Your correspondent on this subject in the issue of April 14 cites an array of facts from which it would seem the proper conclusions should be inferred. I think the whole difficulty arises from a confusion of terms, and by this I mean a want of care to explain the unknown strictly in terms of the known; and I think underlying this error is a misconception as to what an animal is, and what animal strength is, only of course with reference to this particular discussion, i.e., in so far only as they may be considered physical organisms having no reference to the intellectual or moral development, all of which lies beyond the sphere of our discussion.

Purely with reference to the development of physical strength, which alone is under consideration, any animal organism whatsoever must be considered simply in the light of a machine.

A compound machine having two parts, first an arrangement of levers and points of application of power, all of which is purely mechanical, together with an arrangement of parts, designed, first, to convert fuel or food into heat, and, secondly, to transform heat into force, which is purely a chemical change in the first instance, and a transformation of energy in the second. So much for the animal—man or beast—as a machine physically considered.

What then is animal strength considered in the same light? The animal is not creative. It can make nothing—it can only transform. Does it create any strength or force? No. The strength it puts forth or exerts is merely the outcome of this transformation, which it is the office of the machine to perform.

What do we find transformed? Simply the energy, or potential, contained in the fuel or food we put into the machine. Its exact equivalent we find transformed to another form of energy, known as animal strength, which is simply heat within the system available for the working of its mechanical parts. How, then, is this energy which exists in the shape of animal strength used and distributed? This is the question the answer of which underlies this whole discussion as a principle. It is distributed to the different parts of the machine in proportion to the relative amount of physical work that nature has made it the office of any particular part to perform.

Let us see how it is with the bird machine. In course of flight he is called upon to remain in the air, which means that should he cease to make an effort to do this, i.e., should he cease to expend energy in doing it, he would fall during the first second of