his head visible. At two hundred yards the dog detected her master, and went to him directly.

From these tests, Dr. Romanes concludes that the dog distinguishes him from all others by the odor of his boots (1-6), and does not distinguish him in his naked feet (8-11). The odor is probably emitted by the feet, but must be mixed with that of shoeleather to be of service to the dog. This is doubtless a matter of education had the dog been used to following her master when without shoes, the animal would have learned to follow him thus. The characteristic odor cannot penetrate a sheet of brown paper, but a few square millimetres of surface is sufficient to give the dog the clew. The animal is ready to be guided by inference as well as by perception, but the inference is instantaneous (12 and 13 as compared with 2, 8, and 11). Lastly, not only the feet (through the boots) but the whole body emits an odor that the dog can distinguish in a mass of others (15). This order is recognized at great distances to windward (15), or in calm weather in any direction (16): it is not overpowered by anise-seed-oil (14) or by the footprints of another (4).

THE TIME NECESSARY TO PERCEIVE COLD AND HEAT. It is well known that a cold sensation reaches consciousness more rapidly than a sensation of warmth. Dr. Goldscheider of Berlin, whose researches on the hot and cold points of the skin have gained him a well-deserved reputation, has recently accurately measured the length of the time necessary to perceive these sensations. The observations were made on parts equally sensitive to heat and cold, and with intensities of heat and cold equally different from the temperature of the part. The time of contact was recorded electrically by means of a metallic button fixed to the skin. Contact with a cold point was felt on the face after 13.5, on the arm after 18, on the abdomen after 22, on the knee after 25, hundredths of a second. The sensation of a hot point was felt on the same surfaces after 19, 27, 62, and 79 hundredths of a second respectively. This great difference in time has an important theoretical bearing on the physiology of dermal sensations.

Geological History of Lake Lahontan, a Quaternary Lake of North-western Nevada. (U.S. Geol. Surv., Monogr. XI.) By I. C. RUSSELL. Washington, Government. 4°. THIS volume, and the companion monograph by Gilbert on Lake Bonneville, are undoubtedly among the most interesting, if not the most important, contributions hitherto made to the ancient geography of this continent. It must be admitted, however, that the wonderful changes in the aspect of the Great Basin, of which we find here the most conclusive evidence, are scarcely ancient in the geological sense, having been accomplished almost wholly since the close of the glacial epoch, and largely since the advent of

man.

Lake Lahontan, situated mostly within the area now forming the State of Nevada, filled a depression along the western border of the Great Basin, at the base of the Sierra Nevada; while Lake Bonneville, embraced almost entirely in the present Territory of Utah, occupied a corresponding position on the east side of the Great Basin, at the foot of the Wasatch Mountains.

The hydrographic basins of these two water-bodies embraced the entire width of the Great Basin in latitude 41°. Lake Bonneville was 19,750 square miles in area, and had a maximum depth of about 1,000 feet. Lake Lahontan covered 8,422 square miles of surface, and in the deepest part, the present site of Pyramid Lake, was 866 feet in depth. The ancient lake of Utah overflowed northward, and cut down its channel of discharge 370 feet. The ancient lake of Nevada did not overflow. Each of these lakes had two highwater stages, separated by a time of desiccation. In the Lahontan basin, as in the Bonneville, the first great rise was preceded by a long period of desiccation, and was followed by a second dry epoch, during which the valleys of Nevada were even more completely desert than at present. During the second flood-stage, the lake rose higher than at the time of the first high water, and then evaporated to complete desiccation; for the present lakes of the basin (Pyamid, Winnemucca, etc.) are of comparatively recent date, and are nearly fresh, for the reason that the salts deposited

when the quaternary lake evaporated were buried or absorbed by the clays and marls that occupy the bottom of the basin.

As Lake Lahontan did not overflow, it became the receptacle for all the mineral matter supplied by tributary streams and springs, both in suspension and in solution. The former was deposited as lacustral sediments, and the latter as calcareous tufa, or formed desiccation products when the lake evaporated.

The introductory chapter contains a sketch of the Great Basin as the explorer finds it to-day. It stands in marked contrast in nearly all its scenic features with the remaining portions of the United States. The traveller in this region is no longer surrounded by the open, grassy parks and heavily timbered mountains of the Pacific slope, or by the rounded and flowing outlines of the forest-crowned Appalachians; and the scenery suggests nought of the boundless plains east of the Rocky Mountains or of the rich savannas of the Gulf States. He must compare it, rather, to the parched and desert areas of Arabia and the shores of the Dead Sea or the Caspian.

To the geographer the most striking characteristic of the country stretching eastward from the base of the Sierra Nevada to the Rocky Mountain system is that it is a region of interior drainage. For this reason it is known as the 'Great Basin.' No streams that rise within it carry their contributions to the ocean; and the climate is dry in the extreme, the average yearly precipitation not exceeding twelve or fifteen inches.

The area thus isolated from oceanic water-systems is 800 miles in length from north to south, and nearly 500 miles broad, and contains about 208,500 square miles. At the south the valleys of the Great Basin are low-lying, Death Valley and the Colorado Desert being depressed below the level of the sea; but at the north the valleys have a general elevation of from 4,000 to 5,000 feet, while the intervening mountain-ranges rise from 5,000 to 7,000 feet above them.

The mountains exhibit a type of structure not described before this region was explored, but now recognized by geologists as the 'Basin Range structure.' They are long, narrow ridges, usually bearing nearly north and south, steep upon one side, where the broken edges of the strata are exposed, but sloping on the other with a gentle angle conformable to the dip of the beds. They have been formed by the orographic tilting of blocks of the earth's crust, that are separated by profound faults, and they do not exhibit the anticlinal and synclinal structures commonly observed in mountains, but are monoclinal instead. The mountains are rugged and angular, usually unclothed by vegetation, and owe their marvellously rich colors to the rocks of which they are composed, especially the purple trachytes, the deep-colored rhyolites, and the many-hued volcanic tuffs so common in western Nevada, often rivalling the brilliant tints of the New England hills in autumn.

The valleys or plains separating the mountain-ranges, far from being fruitful, shady vales, with life-giving streams, are often absolute deserts, totally destitute of water, and treeless for many days' journey, the gray-green sagebrush alone giving character to the landscape. Many of them have playas in their lowest depressions (simple mud-plains left by the evaporation of former lakes) that are sometimes of vast extent. In the desert bordering Great Salt Lake on the west, and in the Black Rock Desert of northern Nevada, are tracts hundreds of square miles in area showing scarcely a trace of vegetation. In winter, portions of these areas are occupied by shallow lakes, but during the summer months they become so baked and hardened as scarcely to receive an impression from a horse's hoof, and so sun-cracked as to resemble tessellated pavements of cream-colored marble. Other portions of the valleys become incrusted to the depth of several inches with alkaline salts, which rise to the surface as an efflorescence, and give the appearance of drifting snow. The dry surface material of the deserts is sometimes blown about by the wind, saturating the air with alkaline particles, or is caught up by whirlwinds and carried to a great height, forming hollow columns of dust. These swaying and bending columns, often two or three thousand feet high, rising from the plains like pillars of smoke, form a characteristic feature of the deserts.

Chapter II., on the genesis of Lake Lahontan, contains a summary of the facts which show that the lake filled a compound

orographic basin, resulting from the tilting of faulted beds. The question of outlet is discussed in detail, the conclusion being that the lake did not overflow.

Chapter III. discusses the physiography of the Lahontan basin, describing in detail the valleys and mountains, and its lakes, rivers, and springs, and including numerous analyses of the waters from these three sources. Attention is given to the peculiar playas or broad mud-plains of the arid region of the Far West, as well as to the temporary lakes, called 'playa-lakes,' which frequently flood them.

The physical history of the ancient lake is fully and ably discussed in Chapter IV. Under the head of Shore Phenomena' we find detailed descriptions and illustrations of the terraces, bars, embankments, etc., that were formed about its shores. The highest of the ancient water-lines is named the Lahontan Beach;' and the most conspicuous terraces below this are the lithoid,' dendritic,' and 'thinolitic.' Each of these marks the upper limit of a variety of tufa, from which it derives its name.

Numerous sections are introduced to show the structure and relations of the mechanical sediments, which consist of two deposits of lacustral' marls, separated by a heavy layer of current-bedded gravels; thus recording two lake periods and an intermediate lowwater stage.

Chapter V., on the chemical history of the lake, is especially important. It includes, first, a general account of the chemistry of natural waters as they occur in streams, springs, lakes, oceans, and enclosed lakes or seas, followed by descriptions of the tufas precipitated from the water of Lake Lahontan, the salts precipitated when complete evaporation took place, the efflorescences now forming on the desiccated floor of the lake, and the salt-works of the region. As already indicated, the tufas present three main divisions. The lithoid tufa is a compact, stony variety, and is the oldest of the principal calcareous deposits that sheathe the interior of the basin. Thinolitic tufa is composed of crystals, and was formed in the ancient lake when it was greatly reduced by evaporation. The dendritic tufa has a branching or dendritic structure, whence its name, and it is the newest of the tufa formations.

Chapter VI. presents the life-history of the ancient lake as determined by the abundant molluscan remains and other fossils that have been found. The shells show that the lake was fresh throughout its higher stages. During the period when thinolite was formed, it seems to have been too concentrated to admit of the existence of molluscan life, as no fossils have been found in that deposit. A chipped implement discovered in the upper lacustral beds indicates that man inhabited the Far West during the last rise of Lake Lahontan.

Chapter VII. is a brief résumé of the preceding chapters; while Chapter VIII. is devoted to a discussion of the quaternary climate of the Great Basin, the periods of greatest lake-expansion being correlated with the two glacial epochs of the Sierra Nevada, and believed to indicate cold and moderately humid periods.

In Chapter IX. we have a summary of the evidence bearing on the determination of the geological age of the lake. The conclusion reached is that it existed during the quaternary, but was more recent than the date usually assigned for the close of the glacial epoch.

The tenth and concluding chapter contains an account of the orographic movements that have affected the Lahontan basin since the last high-water period, including a map showing all the postLahontan faults, some of which are marked by exceedingly fresh escarpments, and are evidently still in process of formation.

The illustrations are profuse and admirably executed, and Mr. Russell's style is throughout clear and graphic. Details are mainly kept in the background, or presented in tabular form; and it is probable that both in general interest and educational value this monograph is excelled by none of the publications of the Geological Survey.

Elements of Geodesy. By J. H. GORE. New York, Wiley. 8°.

THE present publication is a treatise on some geodetic operations, and intended to give the beginner a clear insight into the subject. It begins with a brief historical sketch of the various attempts to determine the figure of the earth. The former half of the book is

devoted to a description of the instruments and of the elementary operations and methods of plane geodesy, but the principal object. of the author is to describe the methods of spheroidic and geoidic geodesy. The student who begins to study this important branch of geodesy will, or at least ought to, be conversant with the instruments applied by geodesists, with the theory of least squares, and with the calculation of triangulations, which are set forth at some length in the first part of the book. On the other hand, the beginner, who will find some valuable and practical hints in the chapters on base measurements and the field-work of triangulations, will miss a discussion of topographical methods and operations. The book would become far more useful for the beginner, who must study the simpler geodetic operations before beginning with the measurement of the figure of the earth, if a description of the methods and theories of topography were included in the plan. The development of each formula is very complete, and the results are given in the shape that the majority of writers have considered the best. Examples are given to illustrate the application of the formulæ. The student will find at the end of each chapter a list of books referring to the subject under discussion. F. B.

NOTES AND NEWS.

As we go to press we have obtained a copy of the opening remarks of Prof. S. P. Langley, president of the American Association. Professor Langley spoke as follows:

MEMBERS OF THE ASSOCIATION,- While, for the main purpose of our coming here, we are all of one mind, some must remember a peculiar pleasure in their first attendance, when they came to these meetings as solitary workers in some subject for which they had met at home only indifference, and held themselves alone in, till here, with a glad surprise, they met others, too, caring for what they cared for, and found among strangers a truer fellowship of spirit than their own familiar friends had afforded. With such communities of purpose wherever two or three among us are gathered together, it is a happy thing that we cannot remain strangers; for doubtless, of the many here who have habitually breathed "the calm and still air of delightful studies," there are few but know by experience how hard it is for one coal to keep alight alone, and how especially good it is for the solitary workers to be brought at times into the warmth of companionship. To a great many of us, then, it may be counted as the very chiefest good of such an assembly as ours to-day, that here each meets some one with a kindred glow, and finds that interest and sympathy from his co-worker without which the scientific life would be but too cold. It is most fortunate, nevertheless, that our happy constitution as a body, not only of investigators in science, but of teachers and lovers of knowledge, brings those here in greatest numbers who disseminate as well as produce it, and who are skilled to recognize the value of the newly mined product when brought into this public exchange of ideas. We must admit here, that foolish ideas as well as wise ones are brought to this open mart, and that, in dealing with the variety of papers now presented for acceptance, it becomes almost as hard a task for us to shut out folly as to entertain wisdom; for, after all, who are we that judge, and how can we say "wisdom is in us to decide," when it is chiefly because we are ignorant that we are here? Probably the only rule is that taught by experience, that since art is long and life short, experience difficult and judgment uncertain, knowledge commonly advances best by such little steps, that one foot is not lifted till the other is securely planted on the solid ground of fact. On the whole, then, while we agree that some rare visitors have come to us over the “high priori road," do not let us welcome without scrutiny all those who would walk over it into this association's domain. At the same time, in view of our ignorance as to the real nature and causes of things, I would plead with those of you who are judges, for a large tolerance, even of what seem to be errors of speculation, when these are found in company with evidence of a faithful original study of facts; for we shall then have, at any rate, done our best not to turn away Truth, even if she has come to us in an unfamiliar dress. And now I can only congratulate this assembly of her followers on a meeting which opens so auspiciously, and express the hope, that whether in the new knowledge which we may take to the section-room or find there, or in the

social pleasures the gathering brings, this may fulfil its large opening promise of being a fruitful and happy season to us and to our association.

- Dr. E. Naumann, late director of the geological survey of Japan, has published an essay on the influence of the structure of the earth upon the phenomena of terrestrial magnetism. His researches in Japan show that the magnetical lines are to some extent influenced by the fossa magna, a great fault which crosses the islands in a direction south-east by north-west. By studying the direction of the magnetical lines in connection with the geological structure of other countries, the author comes to the conclusion, that, in the vicinity of faults and folds, the magnetical lines show remarkable irregularities, and that a connection exists between both phenomena. Recent researches by Ciro Christoni on the intensity of terrestrial magnetism in Italy (Atti della R. Accademia dei Lincei, 1887, p. 200) show irregularities of the magnetical elements in the eastern part of Venetia, on the western part of the coast of Liguria, and in Val Pelice. These places coincide with centres of seismical disturbances, and suggest a connection between geological and magnetical phenomena. It seems, however, that the available material is still too incomplete for a thorough study of the question at issue, the magnetical surveys not being of a sufficiently detailed character.

- Charles E. Putnam of Davenport, Io., died July 19.

- Those interested in Spiritualism will read with special interest Prof. Carvill Lewis's account of two sittings with the noted English medium, Englinton. This medium is such a tower of faith to believers, and has deceived so many, that so glaring an exposure of his methods as Professor Lewis gives is especially valuable. The article is published in the Proceedings of the English Society for Psychical Research, May, 1887.

-The readers of Science know from our notes on the exploration of Africa how rapidly one discovery follows another, and that it is difficult to keep a map up to date. This fact has induced J. Perthes to publish a second edition of his large map of Africa in ten sheets (14,000,000). The student of the geography of Africa will find this map, which contains an enormous amount of detail, and which is in every respect up to the date of publication, a valuable help in his researches. The routes of explorers, the tribes with whom they came into contact, and the character of the land they traversed, are shown in the map; deserts, steppes, and regions with tropical vegetation, including savannas and woods, being distinguished by different colors. An important feature of the map, and one necessary for the critical study of geography, is the distinction between countries which are really explored and those which are known by report only; the former being written with heavy letters, the latter with light ones. The new edition, of which two sheets-Kongo and Abyssinia - have been published, contains so much new material, that the section Kongo' is practically a new map. The results of the journeys of Kapello and Ivens, Reichard, von François, Kund and Tappenbeck, Wolf, Büttner, Grenfell, Junker, and the observations of Captain Rouvier, have been used in constructing this sheet. The important results of these journeys were published in our map of Central Africa some time ago. The observations of Chavanne and other visitors of the Lower Kongo induced the author, H. Habenicht, to include that region in the zone of steppes occupying south-west Africa. In Section 6, 'Abyssinia,' the routes of Cecchi and Chiarini have been made use of, and what will be welcome to most readers - Emin Pacha's province, his stations, and those of the Kongo Free State, have been marked by separate colors. The political boundaries have been corrected according to recent treaties and annexations.

LETTERS TO THE EDITOR.

The attention of scientific men is called to the advantages of the correspondence columns of SCIENCE for placing promptly on record brief preliminary notices of their investigations. Twenty copies of the number containing his communication will be furnished free to any correspondent on request.

The editor will be glad to publish any queries consonant with the character of the journal.

Correspondents are requested to be as brief as possible. The writer's name is in all cases required as proof of good faith.

The Sonora Earthquake.

THE past month has been spent by me in Sonora, U.S. Mexico, in examining the scene of the greatest disturbances during the re

cent earthquake of May 3. This trip has required mountain-travel of about seven hundred miles, horseback and on foot; fully onehalf, the latter. While it is impossible now to give the complete results of my explorations, a brief summary may prove interesting.

There is not now, nor has there been, lava eruption or crater volcano. I visited every locality in the Sierra Madres where such phenomena had been reported fruitlessly. There is a grand fault extending along the eastern side of the San Bernardino and Yaqui River valleys for nearly one hundred miles. This fault has a general northerly and southerly strike, with a dip of from 45° to vertical; and the difference in level of the two sides is for fifty miles an average of eight feet. It lies close to the foot of the mountain-ranges, where the mesa drift joins the steeper part of the chain, until it crosses the Yaqui, where it goes directly into the mountains. There are numerous minor faults and fissures; and

the entire valley of the San Bernardino is apparently sunk from two to four feet. The relative level is changed that much. This condition exists also on the Babispe River above and for some distance below Babispe, and on the Yaqui at and below its junction with the San Bernardino. Almost every water-course in the disturbed area has changed in the same way.

The town of Babispe was totally destroyed, forty-two lives lost out of a population of seven hundred. No other town in Sonora suffered much. Extensive evidence exists of irruption of water, sand, and fiery gases. As stated in my first letter, mountain-fires succeeded the first shock. These were caused by the ignited gases and falling bowlders. Time data in Mexico, away from the railways, are unprocurable, none existing. The general fact that the first shock took place May 3, about 3 P.M., and that it came from a westerly direction, is all that can be obtained.

It is much to be lamented that the ground was not thoroughly explored before the beginning of the rainy season, which set in on the 14th of June with a violence unknown since 1881. This will

cause the obliteration not alone of the extensive and interesting minor details of the disturbance, but of many of the greater as well, particularly in the river-beds where the changes of level have occurred. The town of San Miguel, three miles north of Babispe, and Bacerac, nine miles south, were uninjured. This is, in view of the principal line of disturbance, particularly interesting.

I enclose a hasty tracing of the section, which may aid in showing the location of the fault. This does not show the length, for it is too tortuous. Scale of map is about 40 miles to the inch. The mountains as marked are the famed Sierra Madres.

Tombstone, Arizona, July 14.

G. E. GOODFELLOW.

Chemical Laboratory of the University of Nebraska. So many requests for the plans and a description of the new chemical laboratory of the University of Nebraska have been re

The entrances are in the south and north ends of the building; that in the south being the main one, while the north door is for the convenience of students coming to the laboratories from the other university buildings. Through this, access is had to every work-room in the laboratory, and to the main lecture-room on the second floor. This arrangement brings classes into the lectureroom from the rear, an arrangement that will be appreciated by every lecturer on experimental science.

Entering at the south door, we find ourselves in the vestibule of the first floor. At our right and left, stairways lead to the basement floor, as shown in Fig. 3. Descending to the basement corridor (Fig. 2), at the front is a large vestibule opening by double side-doors into an area where heavy material is received. Under the stairway to our right is a small room containing the gas-meter. Under the left-hand stairway, and extending across the space occupied by the vestibule, is a ladies' toilet-room. Immediately in

Iceived since its erection, as to warrant the belief that a brief description of its general features would be of interest to the readers of Science, and especially to those who are contemplating the erection of similar buildings, or who are interested in the educational growth of the West.

The building is situated on the south-east corner of the university campus, fronting south on R Street. A wide street bounds the east side, while on the north and west is the open campus: thus the building commands an abundance of light from all directions.

Fig. 1 shows the south front and east side. The building consists of a high basement of native limestone, and a two-story superstructure of the finest St. Louis pressed brick, laid in black mortar and relieved by belt courses of rough limestone. The style of architecture is Romanesque, the broad and heavy stone arches and pointed towers giving to the whole an appearance of massiveness and solidity in keeping with its construction.

front of the stairway is the elevator shaft. The room at the right serves as a store-room for the basement laboratories, and as a balance-room for the assay and metallurgical laboratory. The corresponding room on the opposite side of the corridor contains a small upright boiler for furnishing distilled water, and large storage-tanks for hydrogen and oxygen gases. It serves also as a storage-room for acids and as a work-shop. The remaining portion of this floor is taken up by the general laboratory, where students beginning the study of chemistry do their work. This can be used as one large laboratory, accommodating seventy-five students at one time, or, by closing the communicating doors, be divided into two, A and B, A being used as an assay and metallurgical laboratory.

These rooms have high ceilings, and are well supplied with light. They are ventilated by means of the two large flues C and D, each of which is eight feet broad, and a series of smaller flues built into the side-walls, one between each pair of windows. The large

water, drawers and cupboards. These tables carry the smaller hoods, covering the sand and steam baths, and opening into the small flues. Space is also afforded here for such operations as require more room than the ordinary work-table gives.

Passing through the general laboratory, and ascending the stairway at the north end, we find ourselves in the north hall of the second floor (Fig. 3). On our right is a small room for blast-lamps and combustions. On the opposite side of the hall is the office and study of the associate professor of chemistry.

Passing on, we enter the qualitative laboratory. This is intended

Ascending the stairway at the end of the corridor, we reach the corridor of the second floor (Fig. 4). At our left is the quantitative laboratory, with accommodations for twenty students. Communicating with it is a small dark room for the storage of standard solutions.

Passing through the door in the north end of the room, we enter the main lecture-room. This room has a raised floor, placed at such a pitch that the top of the lecture-table can be seen from all parts of the room. It is furnished with Andrews's patent lecturechair, and will comfortably seat two hundred people.