Chapter II: COSMOPOLITAN AND PROVINCIAL FAUNAS.--There are apparently in the (1)

history of the earth periods of widespread or cosmopolitan faunas, alternating with localized or provincial faunas. The cosmopolitan periods are usually times of prevalence of limestones or organic sediments, and the fossils are very abundant. The provincial periods are usually characterized by sandstones and shales or mechanical sediments, and are comparatively poor in fossils. Moreover, it is believed that the cosmopolitan limestone periods are oceanic periods--i. e., periods of wide oceans and lower and smaller continents and little erosive activity, while the sandstone periods, characterized by provincial faunas, are periods of higher and larger continents, and therefore of great erosion and abundant mechanical sedimentation.

Now, according to Chamberlin, these remarkable alternations are due to oscillations of the crust, in which the continents are alternately lifted and depressed. It must be remembered that abyssal faunas are almost unknown among fossils. This is the necessary result of substantial permanency of oceanic basins. The whole geological record is in shallow-water faunas. These shallow waters are along continental shore lines and in interior continental seas. According to Chamberlin again, during a period of continental depression all the flat continental margins are submerged, forming broad submarine platforms, and the lower interior portions of the continents are also submerged, forming wide and shallow interior seas. Under these conditions continental waste, and therefore sand and clay sediments, are reduced to a minimum. Life, animal and vegetal, abounds, and therefore much limestone is formed. The oceans are widely connected with one another, and therefore the faunas are widespread or cosmopolitan. During the period of elevation, on the contrary, the continents are extended to the margin of the deep oceanic basins, the broad, shallow submarine platforms are abolished, the interior seas are also abolished, the shallow-water areas are reduced to isolated bays, and their faunas are peculiar or provincial. Also, elevated and enlarged continents give rise to maximum erosion, and therefore abundant sediments of sandstone and clay, and comparative poverty of life and therefore of limestone. Chamberlin also gives reasons why the oceanic periods should be warm, humid, equable in temperature, and the atmosphere highly charged with CO_[2], and therefore highly favorable to abundant life, both vegetal and animal, while land periods would be drier and cooler, the atmosphere deficient in CO_[2], and therefore cold from that cause and in many ways unfavorable to abundant life.

These extremely interesting views, however, must be regarded as still on trial, as a provisional hypothesis to be sifted, confirmed, or rejected, or in any case modified, in the next century.

Lastly, it is interesting to note the ever-increasing part taken by American geologists in the advance of this science. There has been through the century a gradual movement of what might be called the center of gravity of geological research westward, until now, at its end, the most productive activity is here in America. This is not due to any superiority of American geologists, but to the superiority of their opportunities. Dana has well said that _America is the type continent of the world_. All geological problems are expressed here with a clearness and a simplicity not found elsewhere. We must add to this the comparative recency of geological study in this rich field. In Europe the simpler and broader problems are already worked out, and all that remain are difficult problems requiring much time. In America, on the contrary, not only are all problems expressed in simpler terms, but many great and broad problems are still awaiting solution. For these reasons the greatest activity in research, and the most rapid advance during the next century, will probably be here in America.

"SALAMANDERS" AND "SALAMANDER" CATS.

BY NORMAN ROBINSON.

In many places in the extreme Southern States, especially in what is locally known as the "piney woods," one of the most notable features is the constantly recurring mounds of yellow sand which everywhere dot and, it must be confessed, disfigure the monotonous landscape. These piles of earth are usually nearly circular in form, fairly symmetrical in contour, from six inches to two feet in diameter, and, save where they have been beaten down by rain or winds or the trampling of cattle, about half as high as they are broad. Often these sand heaps are pretty evenly distributed, sometimes so thickly as to cover at least one fourth of the soil surface. If you ask a native the cause of this singular phenomenon, which you will perhaps at first be disposed to consider a kind of arenaceous eruption which has somehow broken out on the face of Nature, your informant will sententiously reply, "Salamanders!"

All this disfigurement is indeed the work of a curious little rodent popularly so named and about the size and color of an ordinary rat. He is never seen above ground if he can possibly help it. He digs innumerable branching underground tunnels at depths varying from one to six feet, and these mounds of sand are simply the "dump heaps" which, in his engineering operations, he finds it necessary to make.

After carrying the excavated earth to the surface this cautious little miner takes the greatest pains to cover up his tracks. No opening into his burrow is left. How he manages to so carefully smooth over his little sand mound and then literally "pull the hole in after him" is as yet unexplained. The work is mostly done at night, when observation is especially difficult. Sometimes, when he is a little belated and the early morning twilight admonishes him that it is "quitting time," he gets in a hurry and slights his work. Then a little depression at the top of the mound tells where he has made a hasty exit. Ordinarily the rounding out of the sand pile is as deftly done as though it had all been managed from above. Indeed, the feat actually accomplished by this little underground builder appears more puzzling the more it is considered. The most skilled human engineer would confess his inability to thus pile up a mound of loose sand, go down through it, leave the top perfectly smoothed over, and, with no supports save the sand itself, to so fill up the passageway above him as he went down that not the slightest mark should be left to indicate his pathway of retreat.

Even if you dig into and under one of these sand mounds you will find very little to betray the builder's whereabouts. It is seemingly all solid earth, and unless you know exactly when and where and how to dig you will probably give up the search in disgust, with your labor and your backache but no "salamander" hole for your pains. Indeed, the cunning of this little rodent in hiding his burrow is quite as conspicuous as his skill in digging it. "Strategy" is his strong point. If by any chance you come upon his burrow it is probably an old abandoned one that is closed up and leads nowhere. The chances are ten to one that his real burrow is rods if not furlongs away.

Provided you can find the last mound he has built and not more than four or five hours have elapsed since its completion, by digging diagonally to the right or left, at the distance of a foot or so, you will have a fair chance of encountering his burrow. He is probably near by, resting from the severe labors of the previous night. If you give him time to get his nap out and finish his job, your wiser plan will be to stop hunting and digging a little before you begin.

Why this little underground dweller should be called "salamander" is one of those mysteries of popular nomenclature which is seemingly inexplicable. There is certainly nothing in the habits or appearance of the animal to suggest the fabled fireproof batrachian. Like some other lovers of darkness, he has quite a number of _aliases_ by which in various portions of the South and West he is known. "Gopher," "pouched rat," "hamster," and "muelos" are some of the titles by which he is locally known. "Salamander" appears to be the most generally accepted one.

This enterprising little rodent belongs to an ancient if not honorable family. By naturalists he is generally known as "pocket gopher," and is classed among the _Geomyidæ_. Some fifteen known species have been recognized, with possibly more to hear from, and with a habitat extending quite across the continent. The Florida species is probably _Geomys tuza_ (Ord.), and though not as large as one or two others, is quite the peer of any of his cousins in enterprise and ability to look out for himself.

The illustration given is from what is probably the only photograph of a living "salamander" ever taken. Mr. Geomys is not a model "sitter." No unwilling candidate for the "rogues' gallery" has more decided views on the subject of having his picture taken. In a general way, it may be said that he doesn't pose for anybody. Precisely how this prejudice was finally overcome it is needless to state. Perseverance and "snap shots" were too much for our recalcitrant rodent. In the matter of "looking pleasant" it must be conceded that Mr. Geomys was a little intractable.

The fore legs and feet of the "salamander" are worth studying. They remind one somewhat of those of the mole, but are more stoutly built, with much longer claws, and are evidently designed for harder tasks. They are controlled by powerful brachial and pectoral muscles, and, as we shall see, are not only special tools adapted to special and difficult work, but work which requires an enormous expenditure of physical force.

The engineering problems which this little troglodyte has to solve are far and away ahead of any that the New York Rapid-Transit Commission has to deal with. It is very much as though a single miner were placed over in Hoboken, a hundred feet below the surface, with instructions to tunnel under the Hudson River with no tools except his hands, without a chance of seeing daylight until he reached it on the New York side, and with the added conditions that all the excavated earth should be carried out at the eastern opening of the tunnel, and finally that he should obliterate all marks of his work and, as he retreated into his tunnel, pack the exit shaft above him so tightly and so deftly that it is impossible to trace its course!

How our little fur-coated engineer solves all these problems is as yet a mystery. We only know that he does it. He has a steam engine in his shoulders and shovels for hands, but his exact methods of using them is as yet largely a matter of conjecture. Only two plans of operation would seem to be possible. One would be for the "salamander" to first carry the excavated earth all to the rear into some portion of his already finished tunnel, and finally, when the outward exit is completed, to carry it back again and deposit it on the surface. This, of course, involves a double transfer of all the earth removed. It is more likely that the "salamander" first forces a narrow passageway along the line of his future tunnel in a way similar to that pursued by the mole. The latter animal has the advantage of working near the surface, and the earth always yields along the line of least resistance, which of course is upward. Four or five feet down there is no such line, and the amount of force required to push the ground aside must be something enormous. When the "salamander" comes to the upper air the work of excavation and enlargement begins. He then piles upon the surface all the earth that he can not use in obliterating his upward passageway. As the writer has frequently observed fresh sand mounds hundreds of feet from any others, he is inclined to believe that this is the real method pursued.

The exceeding care which the "salamander" takes to leave no opening into his subterranean home arises, no doubt, from his horror of snakes. In this respect no woman can surpass him. His antipathies to reptiles are probably the accumulated embodiment of hundreds of centuries of ancestral experience. He is aware that these hereditary enemies of his race are of a very investigating turn of mind, and put in a good deal of spare time when awake in crawling into and exploring any tempting hole they may discover. And so Mr. Geomys, like the sensible fellow that he is, not only takes good care to shut and lock his front gate every time he is compelled to go through it, but he blocks up the whole passageway and does his best to convince trespassers that it is all a mistake to suppose that there ever has been any roadway leading to his underground home.

Indeed, it is by taking advantage of this morbid antipathy to intruders and daylight that our little underground dweller is usually caught. If by skillful digging a recently formed burrow is reached, one may be reasonably certain that in from five to ten minutes Mr. "Salamander" will be on hand to see what has happened and to repair damages. A shotgun kept steadily aimed at the opening, and with a quick pull on the trigger the instant the slightest movement in the sand is seen, "fetches" him every time. Another very successful method is to place a strong trap right at the opening into his burrow. In making repairs our "salamander" is in too big a hurry to look very carefully where he steps, and so is quite likely to blunder into the trap. He is always caught, however, by one of his legs, and if left any length of time is quite apt to gnaw off the captive limb and thus make his escape. Spartan bravery or love of freedom surpassing this would be hard to find.

The food of _Geomys bursarius_ appears to be exclusively vegetable. Native roots and root stocks, cones and bulbs, together with the root bark of various trees, are eaten by him, and sometimes in a very annoying way. Orange trees are peculiarly liable to his attacks. He gnaws through and around the tap root as near to the surface as he can without disturbing it or in any way calling attention to his work, and not infrequently he continues his depredations until every root of any size is eaten off. This, of course, means the death of the tree.

From the "salamander" point of view, however, the greatest food "bonanza" of all is a sweet-potato patch. "A 'possum up a 'simmon tree" or a "pig in clover" is not more alive to the delights and advantages of the situation. He not only eats all he can stuff, but invites his relatives and friends. Nor is this all. He has learned that in autumn sweet potatoes are liable to suddenly disappear, so he "takes time"--and the potatoes--"by the forelock," and packs them away in liberal measure in his burrow for winter use. So well understood are the ways and weaknesses of this underground marauder that any suspicious mound of earth in a sweet-potato field is the signal for an active campaign of extermination, which ends only in the intruder's flight or death.

The "side pockets" of the "salamander" have already been referred to. They are undoubtedly a great convenience to their owner in carrying food and possibly other things. The capacity of these cheek pouches is about sufficient to give room for a pigeon's egg. They are, however, quite extensile, and can readily be made to hold three or four times this amount. Indeed, the skin and underlying connective tissue are so elastic that these pockets can readily be turned inside out. It is claimed that the "salamander" employs his handlike fore feet to fill and empty these receptacles, using the right foot for the left pouch, and _vice versa_. A gentleman in Florida recently assured me that by a lucky thrust of a spade he once killed one of these mischievous rodents as he was in the very act of cutting off the roots of an orange tree. The cheek pouches of the culprit were filled with fragments of bark which he had gnawed off, doubtless to be stowed away in his burrow.

Why, in a climate where there is almost no winter, where there is very little interruption to vegetable growth and the food supply is practically unlimited, provisions should thus be stored away is somewhat difficult to explain. It is not impossible that it is simply the survival of an ancestral habit acquired during the Glacial period. Or it may be that, like the dog, the "salamander" finds the flavor of old and well-seasoned food more to his taste. All that can be positively affirmed is that this wise little rodent does, occasionally at least, thus _caché_ his food supplies.

One of the most curious results of the existence and habits of this elusive little burrowing rodent is the development of a new and peculiar breed of _Felis domestica_, called "salamander" cats. Ordinary tabbys do not understand or admire the ways of _Geomys bursarius_, or, for some other good and sufficient feline reason, do not include him in their game list. The variety of cats in question, which, so far as the author knows, is confined to Florida, appears to have been developed spontaneously and with very little if any human agency, and is noted for its special skill in catching "salamanders," as well as a decided liking for the sport. Any Mrs. Tabby of this breed, especially if she has a family to provide for, is up betimes in the morning. The particular object of her pursuit is a remarkably early riser, and finishes his day's work before most people have begun theirs. So if there is a convenient fence around the grounds she proposes to hunt she mounts it with the first peep of day, and, with a sharp eye to landward, starts on her tour of observation. Any fresh pile of sand is closely scrutinized. The slightest movement there brings her to the mound with a spring, and she is at once crouching behind it; so when Mr. Geomys comes up in a big hurry with his next load of sand he finds somebody to meet him that is in a bigger hurry still, and so the unsuspecting victim is borne off in triumph.

An estimable lady of the writer's acquaintance who owned one of these "salamander" cats, with a single juvenile pussy to provide for, kept an accurate account of the number of these rodents which she saw this industrious mother cat bring to her offspring in a single month. The number was thirty, and as the month happened to be February this gave, of course, two more than a "salamander" a day.

One other curious observed feature of this new variety of cats is their want of fecundity. The mother tabby seldom has more than one kitten at a birth. The writer once owned a fine female of this breed that scrupulously adhered to the traditional habits of her race.

This particular pussy, like the rest of us, had her family troubles. Her one kitten--probably from its mixed parentage--was always inclined to rebel at the "salamander" diet. There was something amusing to a degree and suggestively human in the old cat's methods of discipline. When she had succeeded in catching a salamander she would always first bring it and lay it down before her mistress, to make sure of the praise and the petting. Then, with a motherly "_meow_," she would call her kitten. That frisky little youngster was always quite ready for his breakfast, but showed a decided preference for the "maternal font." Then the old cat would give him a "cuff" that would send him spinning. Then she would take up the "salamander" and put it down before her hopeful offspring with an air that said as plainly as words could do: "There, now! Eat that or go hungry!" Then her mother love would get the better of her and she would go to licking and petting her disobedient baby, and it would usually end in the kitten's having its own way and satisfying its hunger with milk from the "original package." By persistence and the force of example the old cat finally succeeded in accustoming her offspring to what she evidently thought the orthodox diet of her race.

The writer is quite well aware of the intrinsic difficulties involved in the spontaneous development of any new variety of cats. Still, such branching of types has occurred in the past, and of course is possible now. When his attention was first called to the matter he was inclined to consider it merely an instance of animal education. A fact that came under his personal observation seems, however, hard to reconcile with this or any theory that does not concede the hereditary transmission of acquired habits and tastes.

A kitten of the breed of cats in question was taken when very young and reared nearly a mile away from its mother. When grown it developed the same skill in hunting "salamanders," and the same love for the sport as that for which its mother was celebrated.

Dogs, of course, have long been noted for the readiness with which acquired knowledge, habits, and tastes manifest and perpetuate themselves in hereditary forms. The setter, pointer, collie, St. Bernard, and other well-known breeds will occur to everyone as illustrating this psychic plasticity. Doubtless the cat brain is somewhat less impressible, but there would seem to be good reasons for including it among the educably variable types.

WHAT MAKES THE TROLLEY CAR GO.

BY WILLIAM BAXTER, JR., C. E.

III.

NOTE.--Figs. 28 and 32 are reproductions of photographs kindly furnished by the General Electric Company, while for the view of car, Fig. 30, we are indebted to Colonel N. H. Heft, chief electrical engineer of the New York, New Haven, and Hartford Railroad.

Although the electric railway has been introduced throughout the civilized world with the most remarkable rapidity, replacing cable as well as horse roads, there has always been a strong opposition to the use of the overhead trolley, and in some places, as, for instance, the city of New York, this opposition has been so strong as to prevent the introduction of the system until some other means of conveying the current to the moving cars was devised. Many attempts have been made to solve this problem, and the patents taken out on such devices can be numbered by the hundred and possibly by the thousand. Inventors in this field, however, have not met with all the encouragement they could desire, owing to the fact that, notwithstanding opposition, the overhead trolley has been permitted in all but about three or four of the larger cities of this country, and the greater portion of those of other countries. The principal well-founded objection that can be raised against the trolley is that it is unsightly and destroys the appearance of the street, but those who are opposed to it also claim that it is dangerous, and that underground or surface systems would not be. As a matter of fact it is not dangerous, and there is nothing on record to show that it is. Many persons have been run over by trolley cars, but this is no fault of the overhead trolley; it is due to the fact that street railroads are permitted to run cars through crowded streets at a speed that is too great for safety. Underground conduit cars running at the same speed would run over just as many people. In accusing the trolley of being dangerous it is sought to prove that the current flowing in the wire can do harm; but the history of the numerous roads in existence shows that, so far as human beings are concerned, the trolley current is not fatal, although it can give a decidedly unpleasant shock, such as one would not care to experience the second time. There is just as great, if not greater, liability of obtaining shocks from underground systems as from the trolley, therefore the only real gain that can be made by their use is in the artistic sense. From a financial point of view no underground system so far devised can compare with the overhead trolley; but if any one should devise anything hereafter that can be constructed at the same expense and will not cost more for maintenance it will undoubtedly find an extensive application. Until such a perfect solution of the problem makes its appearance the field for these devices will be confined to cities like New York and Washington, where the overhead trolley is not permitted.

Every system of conductors that dispenses with the overhead wire is called by the layman an underground trolley, but, properly speaking, these systems may be divided into surface and subsurface conductors. Both of these may again be divided into exposed and inclosed conductors, and also into continuous and sectional conductors. Finally, we may designate the various modifications as mechanical, electrical, and magnetic, the mechanical being those that accomplish the result by purely mechanical means, the electrical being those that employ electrical devices, and the magnetic those that depend for their action upon the attraction of magnets. The principal difficulties that the inventors in this field have to contend with are the cost of construction and the effective insulation of conductors. With the overhead trolley the current flows out from the power house to the cars through wires carried on poles, and the poles are themselves good insulators; but to make the work doubly sure the conductors are secured to glass insulators, which are practically perfect. The current returns to the power house through the ground and the track rails. As it is easier for the current to circulate in a short path than in a long one, there is a continual tendency for it to jump from the overhead wire through the insulation to the ground, but this is effectually prevented by the very perfect character of the insulation. When the outgoing and incoming wires are both placed upon or underground the strain upon the insulation is very much increased, for then instead of the two lines being separated by fifteen or twenty feet of pole, which is a very fair insulator, they are separated by only a few inches of earth or perhaps metal, the first of which is a fairly good conductor, while the last is a nearly perfect one. It is evident, therefore, that the insulation proper in an underground or surface system must be of the highest order. If the conduits in which the wires are located could be kept perfectly dry, there would be no difficulty in obtaining insulation that would withstand the strain it is subjected to; but rain in summer and snow in winter will at times cover the tracks and fill the conduits, hence the securing of perfect insulation presents great difficulties. The manner in which inventors have sought to surmount the obstacles can be made clear by the aid of a few illustrations of typical designs.

Fig. 25 shows one of the forms of a class of underground conduits belonging to the inclosed conductor type. The track rails are supported upon the outer ends of large castings, _F F_, commonly called yokes. These are made of such size that the portion below the opening which incloses the conduit may be of sufficient depth to afford the requisite strength to properly support the track. The conductor that carries the current is located at _f_ and is insulated from the casing _j_, which forms the lower half of the conduit, by the stands _g_. From the car a bar, _P_, which is called a plow, projects downward through the slot between the rails, _k k_, and on its end is spread out into a fork, _d_, which carries a pulley, _e_. When this pulley is in contact with the conductor _f_ the current passes through the plow _P_ to the motors upon the car, and thence to the track rails and back to the power house.

As the yokes _F F_ and the conduit casing _j_ are made of iron and are in metallic connection with the track rails, it is evident that if the conduits should fill with water to the depth of the wire _f_ the current would pass directly to the rails, and thus would avoid the longer path through the motors. To prevent this occurrence, the sides of the conduit are inclosed with the sheet-iron covers _c c_, which nominally are in the position shown by the dotted lines _i i_. The plow is also provided with the arms _b b_, upon the ends of which are mounted small wheels _a a_, and these run upon tracks attached to the covers _c c_. As is shown in the figure, the wheels _a a_, running upon the tracks attached to the covers _c c_, cause the latter to spread out to the position in which they are shown. This spreading, as can be readily understood, only takes place for a short distance ahead and behind the plow, but at all other parts of the conduit the sides assume the position _i i_, and thus close the conduit and exclude the water.

It can be easily seen that some difficulty would be encountered in making a tight joint at _h h_, and also that the opening and closing of the sides might not operate as perfectly in practice as upon paper, but it does not follow from these facts that the design is not practical; it simply illustrates that there are many minor difficulties to be overcome in order that complete success may be attained. Many designs operating upon this principle have been patented, and in some of them a great amount of ingenuity is displayed.

Fig. 26 illustrates another type of inclosed conductor which at a first glance appears to be far superior to that just described, but upon closer investigation it is found to be not wholly free from objections that are difficult to overcome. The yoke _F F_, as in the design just described, is made wide enough to support upon its outer ends the track rails _R R_, and is cut away in the middle to an outline conforming with the shape of the conduit. The conductor that carries the current is located at _d_, being supported by the stands _e_. An elastic tube _f_ is provided, which is water-tight and thus excludes moisture from its interior, within which the conductor _d_ is located. On the top of tube _f_ a flexible rail _b_ is secured, and this connects with studs _c_, which are within the tube, as clearly shown in the drawing, and so situated that they may be forced down into contact with _d_. Normally these studs are separated from _d_, but when the car comes along, the wheel _a_, mounted upon the end of plow _P_, flattens the tube _f_ and thus forces one or more of the studs _c_ into contact with _d_. The distance between the studs _c_ is such that at least two will always be in contact with _d_, thus insuring a continuous electrical connection with the motors so long as the plow is depressed.

The first impression upon looking at this design would be that it is entirely free from objections; for if we assume that the tube _f_ is made of rubber, we can see it in our mind's eye springing up after the plow passes by and thus separating the contacts _c_ from _d_, and at the same time yielding freely to the pressure of the wheel _a_. All of this is true, but rubber is not very durable when under such exposed conditions, and to maintain a length of several miles of it in a perfect state for even two or three years could not reasonably be expected; and if it became necessary to renew the tube oftener than this the cost of maintenance would be entirely too great. There is another objection, however, which is more serious, and that is that the conduit will gradually fill up with dirt, and this pressing against the rubber tube would force it out of shape, and thus cause the contacts _c_ to bear permanently upon _d_, or else to become so far displaced that they would not touch it when depressed by the plow.

As the rubber tube can not be depended upon, inventors have sought to improve the construction by using sheet steel and making the tube flatter and much wider, so that a section of it would present an outline much resembling an elliptic carriage spring. Such a construction will meet the requirements as to strength and the retention of the contacts _c_ in their proper position; but steel expands when warm and contracts when cooled, therefore a long tube would be stretched so much in winter that it might pull apart, while in summer it would be compressed and tend to buckle up and thus be forced out of place. These difficulties can be overcome by providing expansion joints at suitable intervals, so that they are not necessarily proof of the impracticability of devices based upon the principles involved in this design; they simply serve to forcibly bring to mind the fact that the path of the inventor of underground systems is not strewn with roses, no matter in what direction he may turn to find a solution of the problem.

The object in the designs Figs. 25 and 26 is to shield the conductor so that it will remain dry should the conduit be filled or partially filled with water. If water could be excluded from the conduit, the casing _j c c_, in the first figure, and the tube _f_, in the second one, would not be required, for there is no difficulty in providing an insulating support that will hold the conductor firmly in place and at the same time prevent the escape of the current; but as soon as moisture collects upon the surfaces of the insulating supports it acts as a conductor, and thus renders the insulation of little value. If water runs into the conduit in such quantities as to come in contact with the conductor, then the effect of the insulation is entirely destroyed; the aim of the inventors, therefore, is to provide means for preventing the accumulation of water or moisture around the conducting wire. It can be readily seen that the shorter the conductor the easier it is to protect it, and this fact has given rise to the development of a great number of designs classified as sectional conductors. In these, two conductors are used, one of which is continuous and so situated and insulated that it can not under any conditions be reached by either moisture or water. The other conductor is made in lengths that vary all the way from fifteen to two or three hundred feet. Normally, these short sections are not connected with the circuit--they are dead, as it is called--but when the car comes along, the plow, by acting upon suitable mechanism, establishes a connection between the continuous conductor and the portion of the sectional conductor that is directly under it, and in this way the current passes to the car. As soon as the car passes beyond a section of the sectional conductor, the connection between it and the continuous wire is broken automatically. Some of these arrangements depend upon mechanical devices, such as levers that are struck by the plow and thereby move a switch that closes a connection between the section and the continuous conductor, but in most instances the switch is operated by a magnet, which may be carried by the car or may be arranged so as to be energized as the car approaches it. Designs of this last type come under the head of electrically operated sectional conductor systems. There are other arrangements in which a magnet carried by the car attracts iron levers suitably disposed along the conduit, and these levers close switches that connect the section of conductor under the car with the continuous one. As the levers are actuated by the magnet, they only hold the switch closed while the latter passes over them; thus the electrical connection is made and broken as the car moves along.

Most of the designs in which sectional conductors are used can be placed much nearer to the surface of the street than the types illustrated in Figs. 25 and 26, and this is a decided advantage, as it greatly reduces the cost of construction. Any system that requires an underground conduit, with the yokes _F F_ to support the track, can only be used by roads upon which the traffic is very great, for the cost of construction would be such as to prohibit its use under any other conditions, no matter how successful its operation might be. For small roads with moderate traffic the question of first cost is of paramount importance, and the only system that can offer a satisfactory solution of the problem for these is one that does not require an underground conduit.

Although many patents have been taken out for systems similar to those described in the foregoing, nothing has been done practically with any of them except in an experimental way. Some are in operation on small roads in out-of-the-way places, being intended principally to illustrate the practicability of the system and thus assist in promoting its introduction elsewhere, but the system that has been adopted in a commercial way is one in which no attempt is made to shield the conductor from moisture and water, and for its successful operation dependence is placed entirely upon the proper drainage of the conduit. This system is well illustrated in Fig. 27. The plow _P_ carries upon its end two brushes, _b b_, which are insulated from each other. These brushes rub against the conductors _a a_, which are made of bars of channel iron and are well insulated from the yokes _F F_ and the conduit casing to which they are attached by means of the supports _c c_. In the construction shown in the figure the current comes from the generator through one of the _a_ bars and returns through the other, but both bars can be used to conduct the current from the generator, in which case the return can be effected through the track rails, just as in the designs already considered. If both the bars _a a_ are used to convey the current from the power house the insulation between the brushes _b b_ is not required. To avoid the accumulation of water in the conduit the drain _G_ is provided with outlets _d_, located at suitable points.

Although this system is the simplest that can be devised for use in streets or public highways its construction is very costly, so much so that it can only be used in cities where the traffic is so great as to require the running of cars on short headway; and, furthermore, it can not be operated with any degree of success except in municipalities where there is a good sewage system. During the summer months it is liable to be more or less impaired by heavy showers, but the trouble in such cases is only temporary. In winter time snowstorms are liable to affect it in the same way, especially if, after a heavy fall, a warm wave comes along and produces a rapid thaw.

From the fact that no attempt whatever is made to protect the conductors, one would naturally suppose that every time there is a rain the road would be compelled to shut down; for, as the slot through which the plow travels is open, water can enter the conduit with the greatest freedom, and, in trickling down the sides, would be caught to some extent upon the brackets _c c_, and thus make its way over to the channel bars _a a_, and thereby destroy the insulation. Practice, however, shows that this action does not take place, at least not so often as to produce any serious trouble. The roads that are operated by electricity in New York, and also the lines of the Capital Traction Company, of Washington, D. C., employ this system, and they have been in operation a sufficient length of time to fully demonstrate that the difficulties actually developed by the action of the elements are not of a formidable character. On one occasion the Sixth Avenue road, in New York, was compelled to stop its cars for a short time just after a severe snowstorm, but the failure was not due to impairment of the insulation, according to the statements of the officials of the company, but to the fact that the melted snow froze upon the track and caused the wheels to slip around without sending the car ahead. The fact that other roads in New York, belonging to the same company, are being equipped with the system, is proof that, upon the whole, its practical operation is regarded as satisfactory; but it is very evident that it is not the final solution of the problem. A system to be a decided success must cost very little more than the ordinary overhead trolley, and its construction must be such that it will not easily get out of order. If it is not inexpensive it will not come into use except in places where the authorities will not permit the overhead wires. A surface or underground system ought to be more durable than the overhead, as the wires are not liable to be injured by high winds or the accumulation of ice and snow; and, furthermore, as the conductors are below the ground the danger of burning out motors and generators by lightning would be eliminated, and this is a serious matter with all trolley roads, especially in cities. Country roads do not suffer so much from lightning, because when there is a heavy thunderstorm the generators are stopped and the trolley poles are pulled away from the wire, the cars remaining stalled on the track until the storm passes over. This course can not be pursued by city roads, for the passengers feel that, lightning or no lightning, they must reach their destination, therefore the cars must continue to run and take their chances. Lightning, however, does not strike trolley lines as often in cities as in the open country, owing to the fact that there are so many iron buildings and roofs to attract it in other directions.

Fig. 28 shows the appearance of the street surface when an underground system such as is illustrated in Fig. 27 is used. This figure is a photograph of the Capital Traction Company's lines in Washington. After looking at this picture one can not deny that the appearance of the streets of a city is greatly improved when the overhead wires are removed, but underground systems which require a plow to run in a groove are not without objection, for the groove forms a dangerous trap into which the narrow-tired wheels of light wagons can readily drop, and the toes and heels of horseshoes can be caught. Thus, unless the slot can be dispensed with the greater beauty overhead is obtained at the expense of increased danger on the street surface. There are quite a number of underground conductor systems in which the slot is not used, the current being conveyed to the car by contact made with plates set at suitable intervals between or along the sides of the tracks, and on a level with the street surface. Many of these arrangements appear to be quite practical, but none of them can attract the attention of railroad managers unless it can be constructed at a reasonable cost.

About two years ago the New York, New Haven, and Hartford Railroad published a report of the performance of a branch line that was equipped with electric motors, the current being conveyed to them by means of a third rail. Some of the sensational dailies at once took the matter up and heralded the third rail to the public as something entirely new and sure to supersede the trolley. Now, as a matter of fact, the third rail is one of the oldest arrangements that have been used, and was in daily operation in Baltimore in 1886. It is a very cheap system and well adapted to roads owning the right of way or running upon elevated tracks, but could not be used on public highways or streets. The third-rail system in its simplest form is shown in Fig. 29, which represents a section through the roadbed. The log _A_ represents a tie or sleeper, and _c c_ are the track rails, while _b_ is the third rail through which the current passes to the motors. Between the rail _b_ and the tie _A_ is placed a piece of insulating material, _a_, of such dimensions as may be necessary. If the track is high above the surrounding ground, so as to not be submerged when there is a heavy fall of rain, _a_ may be thin, but otherwise it must be of sufficient thickness to raise the rail above the high-water mark. The car is provided with a wheel or brush to bear upon the rail _b_.

This is the construction used upon the New York, New Haven, and Hartford Railroad, as can be seen from Fig. 30, which is a photograph of a section of the road. The third rail, it will be seen, is raised but slightly from the ties, just about as shown in Fig. 29. One objection to this construction is that persons and animals can receive shocks by touching the center rail and one of the side ones at the same time, as, for example, by standing with one foot on each. Such shocks would not prove fatal to men, as the currents used for railway work are not of a sufficiently high electro-motive force to produce death, but the shock is nevertheless very severe. Horses and cattle would be killed outright, as these animals are not able to withstand as strong a shock as human beings. To render the third-rail system safer, and also to improve the insulation of the conducting rail, the construction illustrated in Fig. 31 has been devised. The only difference between it and Fig. 29 is that the rail _b_, instead of resting upon the ties between the tracks, is carried upon a side support _c c_ and is housed in with boards _a a_. To take the current from it a wheel is mounted upon a shaft projecting from the side of the car truck.

From the foregoing brief description of the essential features of the several systems devised for conveying current to the moving car by means of conductors placed underground or upon the surface, it can be seen that while the result can be accomplished in many ways, and is actually accomplished in a number of instances, nothing has been brought forward so far that is as free from objection as the simple trolley, if we disregard the unsightliness of the latter. It is this unsightliness that has created a demand for something else, but the substitutes, while capable of doing the work, are far more costly and can not be said to be as reliable under all conditions of weather.

The sphere of action of the electric-railway motor is not confined to street railways or suburban transit, but extends to the legitimate domain of the steam locomotive. In many places electric locomotives are used to move freight trains made up of cars of the largest capacity, this same work having been done formerly by steam locomotives. In the city of Baltimore, the Baltimore and Ohio Railroad uses electric locomotives, of greater capacity than any steam locomotives so far made, to draw trains through the tunnel that passes under the city. The general appearance of an electric locomotive can be judged from Fig. 32, which shows an engine of average size at the head of a long freight train.

MM. Bertaux and G. Yver are quoted, in _La Nature_, as relating in their travels in Italy that between Benevento and Foggia, where the railway passes through a tract of wheat fields, a falcon was observed closely accompanying the train. He would graze the windows, fly over the roofs of the cars and turn, and keep constantly dashing down to the ground by the side of the track. A habitual traveler on the road remarked that he had observed this habit of the bird several times a week. The crafty hawk had observed that the eddy made by the train as it rushed through the air overcame the small birds and made them an easy prey, and it had learned to take advantage of the fact. It was also remarked that this particular train, which was the "fast train," was the only one the bird thus pursued.

A SURVIVAL OF MEDIÆVAL CREDULITY.

BY PROFESSOR E. P. EVANS.

One of the crassest and most impudent and yet most successful frauds of modern times is that recently practiced by Leo Taxil and his associates on the papal hierarchy in their pretended exposures of the Freemasons and the Satanic rites performed by this secret fraternity. On April 20, 1884, Leo XIII issued an encyclical letter in which he divides the human race "into two diverse and adverse classes" (_in partes duas diversas adversasque_): "the kingdom of God on earth--namely, the true Church of Jesus Christ"--and "the realm of Satan." All who are not members of the former belong to the latter, so that there is no alternative between being a good Catholic or a worshiper of the devil. His Holiness then proceeds to show that the headquarters of Satanism are the lodges of the Freemasons, a fact, he adds, fully recognized by his predecessors, who have never ceased to expose and denounce the diabolical character and flagitious aims of these archenemies of the Christian faith. The detailed description of the organization of this order, its devilish purposes, and the horrible crimes committed in order to accomplish them are very queer reading in an official document emanating from an infallible ecclesiastical authority at the close of the nineteenth century. On August 20, 1894, Leo XIII published a decree of the Inquisition putting under ban "Odd Fellows, Sons of Temperance, and Knights of Pythias" as "synagogues of Satan," and excluding them from the sacraments of the Church.

It is no wonder that such an exhibition of credulity, which excited the astonishment of many a Romanist and made all intelligent and unprejudiced persons smile and shrug their shoulders, should have suggested to an arrant wag and incorrigible player of practical jokes like Leo Taxil (pseudonym of Gabriel Jogand) the idea of appealing to this peculiar passion on a grand scale and seeing to what extent the "mother Church" could be led into fraud, as Milton says, like "Eve, our credulous mother." In tracing the development of this audacious plot through all its stages and perceiving by what silly tales and transparent deceptions the Holy Father permitted himself to be duped, one can hardly refrain from exclaiming, in the words of Ben Jonson:

"Had you no quirk
To avoid gullage, sir, by such a creature?"

Leo Taxil was born at Marseilles on March 21, 1854, and was therefore thirty years of age when he entered upon this career of intrigue and mystification. From his childhood he had been educated in strictly Roman Catholic schools, and everything was done by his pious parents and teachers to render him sound in the faith. Long before arriving at man's estate he had thrown off these influences and cast in his lot with unbelievers, although he continued to go to mass, confession, and communion. While a pupil in the Catholic College of St. Louis, at Marseilles, he was strongly attracted to the political views of the radical party as set forth in Rochefort's _Lanterne_, and soon began to write for the press; in 1871 he joined the editorial staff of _Egalité_, and published for two years a humoristic journal--_La Marotte_ (Fool's Bauble). It is not necessary to give a detailed sketch of this man's life. Suffice it to say that he was violently anticlerical, and was repeatedly fined and imprisoned for articles insulting to the Church and to ecclesiastical dignitaries. On December 29, 1881, at Montpellier, he was condemned to pay a fine of sixty-five thousand francs for publishing a book entitled The Secret Amours of Pius IX. He appealed from this decision, and, after repeated efforts, succeeded in having the indictment quashed. A new edition appeared in 1885, and was announced by large placards, in the center of which was a medallion of the Pope's head, encircled with the heads of a bevy of beautiful women, forming, according to the author, a fitting halo for his Holiness. We may add that the sensational revelations contained in this book, as well as in the Scandalous History of the Orléans and similar works, are for the most part mere figments of the imagination recorded as facts, for the purpose of mystifying a credulous public. In 1880 he founded a "Society of Freethinkers," which, with its numerous branches, numbered in a few years about seventeen thousand members. The remarkable success of this movement was due in a great measure to the energy with which he advocated it in the columns of the _République Anti-Clericale_, of which he was the editor.