be over one-half ton. By a law of mechanics, the centrifugal force increases as the square of the speed. Thus, at 10,000 revolutions, the pressure would be fully double that at 7,000.

At 100,000 per minute, if the distance traveled by the bowl could be drawn out in a straight line, it would be more than six miles a minute. The best cast iron free from flaws would burst at a speed of about 6,000 revolutions per minute. Malleable iron at a little higher speed; but the cast steel of which the bowls in the De Laval separator are made have the tested tensile strength of 42,000 pounds or twenty-one tons per square inch: It is not surprising, therefore, that great damage is done when the creamery man is so foolish as to run the separator at a speed of over 10,000 revolutions per minute. We have run our separator up to a speed of about 9,000 revolutions per minute to test it; but in ordinary operations it is run at 6,000 to 7,000 per minute.

There are in this country at present two prominent machines which we will explain in this connection, as the majority of the farmers in this State are unfamiliar with the principles upon which they act. The cut represents a section of the De Laval Separator, and we are looking at it as a person would look at the flat side of an apple cut in halves. "A" is the bowl of the separator supported by a spindle "E" which is set in motion by a pulley "K" in which a belt, driven by steam or horse power, runs. The bowl is supported upon two narrow steel points at "w" which reduces the friction to a minimum. "B" is the iron support for the machine. "s" and "N" are oil cups. The milk is delivered through the tube "b" and flows into a little bowl "d" from which it passes out into the large bowl "A" through an opening not shown in the cut. "C" and "D" are tin pans made to fit closely down over the separator bowl. "y" is the speed indicator for determining the number of revolutions per min

ute.

After the machine has been started and attained speed of over 6,000 revolutions per minute, the milk is let into the bowl through the cock "b" and assumes position in the bowl in layers arranged according to specific gravity. If there be any sand or dirt in the milk, this will be held near the outside of the bowl; then comes the layer of skim-milk, and lastly, next to the center of the bowl, comes the layer of cream. At this high rate of speed, the separation of the milk after it passes from the bowl "d" is almost instantaneous. The skim-milk is forced by the centrifugal force through the tube "e" and out through an opening in the side of it at "c" where the skim-milk is caught in the pan "D" and delivered through the lower spout. The cream rises upon the inside of the bowl, and passes out through a little slit in the top of it at "f" into the cream pan "C" and the cream is delivered from the upper spout. The quantity of skim-milk thrown off may be regulated by a little screw in the bowl at "f" which opens and closes the aperture at "c." This machine works very perfectly and leaves little to be desired so far as the quality of the work is concerned. Several modifications of the principle of this machine have been introduced, but they refer principally to the method of supplying the power. This

particular form of machine is sold by the De Laval Separator Co., 74 Cortlandt St., New York City, or by any of their agents throughout the country. P. M. Sharpless, of West Chester, Pa., manufactures what he terms an "Improved De Laval," which is meeting with extensive sale in the country. The latter manufactures a steam turbine separator in which the power is applied by steam acting upon a small turbine wheel at the bottom of the separator stand. I have not seen the machine in operation and hence cannot state positively as to the efficiency of this form of the application of power to it. The success of the separator depends largely upon having an unvarying source of power, and if left to the direct action of steam, it will be necessary for the steam pressure in the boiler to be maintained uniform to secure the highest efficiency unless some automatic arrangement is devised for regulating the flow of milk to the separator.

The DeLaval Company manufactures two forms of hand machines adapted to the use of small dairymen: one an upright form Fig. 3.

and the other horizontal.

The horizontal machine is represented in the above cut. Our experience with the upright machine has been that it separates the cream satisfactorily; but the labor of turning the machine is very severe. The horizontal machine runs

easier, and is said to do its work fully as satisfactorily. These hand machines will separate about 250 pounds of milk an hour.

The other machine prominently before the people is the "Danish Weston," a cut of which is herewith presented. The bowl of this machine is larger than that of the DeLaval and hence does not have to be run at such high speed. A study of the cut will show the manner in which the milk is separated in the bowl by centrifugal force. The cream stands next to the inside of the bowl and dirt next to the outside; while the skim-milk stands between the dirt and the cream. The cream is skimmed off by means of a tube set to catch it. As it rises in the cylinder, another tube is arranged so that it will catch the skim-milk and carry it off in another direction. These are provided with adjustments so that the quantity of milk taken with the cream can be changed to suit the wishes of the creamery-man at will.` The "Danish Weston" will separate slightly sour milk. The "DeLaval" separator very soon becomes clogged when sour milk is run into it, and for this reason, some creameries prefer the "Danish Weston" machine; especially in sections where it is difficult or impossible to collect all of the milk at the creamery before it has begun to sour. This machine is, however considerably more expensive than the "DeLaval," and skims no closer. It rests with the Creamery Company to determine which kind of machine is best adapted to its use. The Greenbrier Creamery in this State uses the "Danish Weston" machine and I understand is very highly pleased with it. Most of the other creameries of the State use the "DeLaval" or the "Sharpless Improved DeLaval." The "Danish Weston" machine can be secured through the Creamery Package Manufacturing Company, 20 North Clark street, Chicago, or from A. H. Ried, Philadelphia. It can also be had through almost any of the dealers in creamery supplies.

There is but one other separator manufactured in this country so far as known to us that requires our attention, and that is the "Backstrom," which is a most excellent machine, and in some respects I believe it superior to either of the machines named. We have had one of these machines at the station here, and have been well pleased with it. The machine has a shelf in the bowl upon which the skim-milk is forced by centrifugal force, and it is there caught by a tube similar to the arrangement in the "Danish Weston." The cream passes out through an opening at the bottom of the bowl, and is delivered at the side of the stand. In size and ca

pacity, the machine is not unlike the DeLaval. At present, however, the Backstrom Manufacturing Company of New York, which owns the patent, seems to be financially embarrassed, and I believe there are none of the machines upon the market; a matter, I think, that is to be regretted, as it was the cheapest machine offered in the American market, and in our judgement one of the best.