air. It is remarkable how tender and palatable a small pig tastes that has been cooked in a native oven-a well-cooked chicken is not sweeter nor more juicy.

While every Samoan head of a family seems to own his home and small plantation, yet it is not so, for he is but one member of a large family, and simply a stewart over his portion, being subject to the will of the "Matai," or head chief of his family. Because of this condition, families are often moved from one house to another. They are subject to removal for any overt act, or, as a matter of choice, families often move from one island to another; living one year with his folks and another with her folks, and so on, borrowing each other's children indiscriminately. They were seemingly much offended when we refused to let them adopt our little girl, and take her home with them to live. Natural affection as we understand it, between parents and children, does not seem to be very strong. Because of this peculiar interchange it would be next thing to impossible to take a correct census of the natives.

The first sight that greets one on entering a Samoan village, is the almost, and sometimes entirely,nude bodies of the little brown natives, playing in the sandy main street of the village. At the approach of a stranger, they scamper away in fear, and hide themselves behind cocoanut trees, and the posts of houses. They peek at you as you ride or walk through the village, with their big brown eyes set in the fattest and most interesting of faces. The native children have so few games to amuse them, that we were often tempted to introduce tops and marbles among them, that if possible they might sense the joyous delight of our boyhood days. The game of cricket has been introduced among the natives, but is frowned down by the English missionaries, because of the extremes they go to in playing it. One village plays against another for days and weeks, with feasting in the day time and "sivas" native dances, at night, until a famine is threatened in the village because of the entire cessation of work in caring for the crops.

There is a peculiarity in the way the natives do many things, and some of their ways are quite the opposite to ours; for instance, when women hand-print their "tapa" cloth, they strike away from the body instead of drawing the hand and brush towards them. They cut their children's hair with a piece of broken glass, shav

ing the skull like that of a Chinaman, leaving a tuft of hair here and there in a most grotesque manner. Fancy an American mother looking on while these Samoan barbers shave their children's heads, with pieces of broken beer-bottles, fastening the little one between their knees as in a vice, during the operation.

Ava drinking is used to express good feeling and hospitality. While a little piece of ava-root looks like any common piece of root, yet in Samoan custom it is a sign of the most genuine hospitality. Speeches of welcome, and responses always attend its presentation. Altogether it is a most pleasant custom, as it is carried out on Samoa. The drink is made in mild form, does not stupify as on Hawaii, but is considered a good medicine by foreigners. It quenches the thirst, and often takes the place of a meal to the natives. In no other custom more than ava-drinking does one see the caste line drawn so closely between the various degrees of chiefs, matai faipule, tulafale, etc. The highest in rank is served first, or trouble follows, since the natives are exceedingly jealous of rank and genealogy. One would think, to see a "fono," or council of chiefs, (especially if on a Saturday) that they were all old, white-headed men, but on closer observation, you would find this effect the result of their hair, (which is always cropped short and combed pompadore, both fore and aft,) being smeared all over with a slackened lime paste. The lime has two effects. It keeps the head clean and turns the hair a golden brown. After a bath, and a plentiful supply of highly-perfumed cocoa-nut oil spread upon the hair and over the body, many of these seemingly white-headed chiefs change their appearance wonderfully.

LIQUID AIR, AND SOME OF THE EXTRAV

AGANT CLAIMS MADE FOR IT.

BY DR. JAMES E. TALMAGE, OF THE UNIVERSITY OF UTAH.

So many articles treating on the subject of liquid air, the marvelous properties of the substance, and the alleged possibilities of its application to the service of man, have appeared in the magazines of recent months, that additional writings of the kind call for a statement of reason or excuse for their coming forth. The present writer's excuse for appearing in print under the foregoing heading rests on the urgent and repeated requests of the ERA'S editors to this end; and their reasons for desiring such a contribution are probably strengthened by the questionable reliability of the great array of liquid air literature already presented to the reading public. Certainly much that has been published on this subject consists of unproved assertions and of extravagant promises, the fulfillment of which is by no means assured. Prospectuses of three companies have already appeared, each specifying a capitalization of five millions of dollars, and predicting speedy and enormous returns to those who invest their means in the utilization of this new agent of civilization and progress. The careful reader may have observed that the immoderate praise of liquid air as an agent of unprecedented efficiency, and the song of its future triumphs, have been generally voiced through the columns of semisensational periodicals; while scientific journals and publications of acknowledged authority in the special field of physics have been mainly silent on the subject or studiously guarded in their utter

ances.

Demonstrated facts, unsupported theories, and fanciful dreams have been so mingled in current discussions of liquid air, that the lay reader may be unable to distinguish between fact and supposition.

In the first place, what is liquid air, or, more accurately stated, liquefied air? It may be profitable to preface the answer to this question by a few general considerations. We are accustomed to speak of two classes of substances with respect to physical state, viz., solids and fluids; of fluids two sub-classes are recognized, liquids and gases. The essential difference between a liquid and the same substance in a state of gas is one of condensation, the particles of the gaseous substance being brought closer together in the process of liquefaction. Long ago it was demonstrated that by increasing pressure, or by lowering temperature, and more expeditiously by combining both of these operations, certain gases could be reduced to the liquid condition. Increased pressure was usually employed as the means of liquefaction, but experiment soon proved that pressure alone would not insure liquefaction in all cases; and that for each gas there is a certain degree of heat, commonly known as the critical point of temperature, above which the gas cannot liquefy, however great the pressure applied. It has also been proved that for every gas there exists a critical point of pressure, below which liquefaction is impossible even though the temperature be greatly reduced. Air, which is not a single gas but a mixture of gases, was one of the most obstinate substances to liquefy. Its critical temperature has been proved to be about 140° C, and its critical pressure 39 atmospheres, or 585 pounds to the square inch. Liquefied air then is the ordinary atmospheric mixture of gases, so condensed by pressure and cold as to be brought into the state of a watery fluid.

Means of producing intense cold have been eagerly sought with the hope of employing such in the liquefaction of gases. The common methods now used are based on the fact that heat is absorbed in the process of gas expansion. It is generally known that when a gas is compressed by mechanical means it becomes warm. Conversely, when a gas so compressed is allowed to expand, heat is absorbed, and the bodies with which the expanding gas is in contact will be robbed of their sensible heat. Upon this princi

ple the expansion of compressed ammonia in tubes is made a means of refrigeration.

In 1879, Callette liquefied air in small quantities by means of pressure mechanically applied, combined with the cooling effect of expanding gases. Six years later, Solvay produced liquid air in greater quantities by employing a cumulative method of cooling, the principle of which may be stated briefly as follows: Air that has been compressed is deprived of part of its sensible heat by external cooling; it is then allowed to expand to its volume before compression, and is again compressed, cooled and allowed to expand, the process being repeated until a very low degree of temperature is reached. This method has been improved upon by Linde, of Munich, in 1895; and during recent months, by Mr. Charles E. Tripler of New York. The gentleman last named has been so successful in his efforts that liquid air is now produced at a very low cost, and in quantity sufficiently great to warrant the expectation that its adaptability to practical purposes may be thoroughly tested by experiment. While the means of producing the substance were so costly and difficult, practical experiments, on a large scale, were not attempted. It is interesting to note that in Mr. Tripler's ingenious and highly efficient method of applying the principle of cumulative cooling, compressed air is employed as the gas which cools by expanding. Liquefied air is air in an extreme state of compression; this substance therefore may be and has been employed as a cooling agent, which by its own evaporation and subsequent expansion, cools, and eventually liquefies other, though smaller quantities of air. The principle underlying the process by which air is liquefied on the cumulative plan of cooling, is thus concisely described in a recent paper by Mr. E. S. Wicklin, of Chicago. It should be understood that the description is not that of any particular machine. "Air compressed to about 2,500 pounds to the inch, and cooled by being passed in pipes through a bath of running water while thus compressed, is carried through coils of pipes to a receiver several feet away. Into this it is discharged through pinholes not large enough to reduce the pressure in the coils. As fast as set free in the receiver, the air expands to nearly its original volume, falling in temperature perhaps a hundred degrees or more. From the receiver the air flows