6

FIG. 8.-Eel swimming in a horiz ntal plane. The horizontal line oo shows plainly the inclination of those lines which join the crests and troughs of the waves formed by the body, so that the velocity of progression of the animal is expressed by the inclination of the line oa.

as these, Prof. Marey does not here conclude his observations, but has constructed a special piece of apparatus, as shown in Fig. 9, for recording the movements of microscopical objects. The general working of this apparatus can be seen at a glance. c is the large condenser which concentrates all the light from some artificial source on to the small holder p, in which the object is placed. The micrometer objective marked o,

FIG. 7.-Series of phases performed by a star-fish in turning itself over. Fig. 8, illustrating an eel swimming horizontally, brings out clearly the wave produced by the effect of the un

FIG. 9.-Special piece of apparatus for studying the movements of microscopical objects.

is placed on the other side of this holder, but in the axis of the condenser. The micrometer head B regulates the distance of p from o, and can be moved either by the rod mv, or by its milled head. An important adjunct to the instrument is the microscope that is placed obliquely at the side of the camera; by its means, and by that of a small prism that can be placed in the axis of the light by simply pulling or pushing the knob P, the object about

and illustrates the movements of Vorticelle, which retract their stalks in spiral fashion. Many other proposals, not yet carried out, are mentioned by Prof. Marey, and include the production of photographs showing the movements of blood corpuscles in the capillary tubes, the intimate actions of the contraction of the fibre of the muscles, and the waves which pervade them

Prof. Marey also applies chronophotography to move

FIG. 11.-Series of positions taken up by a falling ball studied by chronophotography on a fixed plate.

ments of objects in physical as well as in biological science, but although several cases are mentioned, we will only refer here to the instance he gives of the falling ball (Fig. 11).

The intervals between each image of the ball, although different in space, are equal in time, and the illustration brings out clearly the gradual increase of the velocity;

good results. The branch that we look forward to being greatly extended is that in which the microscope takes the prominent part. W.

SIR GEORGE BIDDELL AIRY.

WE greatly regret to have to record the death of Sir

George Biddell Airy, whose name has been familiar to the scientific students of more than one generation. He died on Saturday evening last, in his ninety-first year. In the summer he received by a fall an injury which rendered a surgical operation necessary. Although at the time this seemed to be successful, he never really recovered from the shock to his system.

On October 31, 1878 (vol. xviii. p. 689), we published a portrait of Sir George Airy in our series of "Scientific Worthies," and at the same time we gave a full account of his work as a man of science. We need not now, therefore, do more than note the main facts of his career. He was born at Alnwick, Northumberland, on July 27, 1801, and received his early education at private schools in Hereford and Colchester, and at the Manchester Grammar School. In 1819 he entered Trinity College, Cambridge, as sizar. Here he soon gave proof of a remarkable aptitude for mathematics, and in 1823 he graduated as Senior Wrangler. In the following year he was elected a Fellow of his College, and in 1826 he became Lucasian Professor of Mathematics. He was full of enthusiasm for experimental science and applied mathematics, and in 1824-25 had published papers on "The Lunar and Planetary Theories," on "The Figure of the Earth," on "The Undulatory Theory of Optics," on "The Forms of the Teeth of Wheels," and on "Escapements." After his appointment to the Lucasian Professorship, he continued to make important contributions to the knowledge of such subjects, devoting himself with especial ardour to the study of undulatory optics, which was at that time a new field of research.

He was elected Plumian Professor of Astronomy in 1828, a position with which was associated the directorship of the Astronomical Observatory. Here he superintended the erection of several instruments, andin accordance with the example set by Maskelyne, and followed by Bessel and Struve - introduced a thoroughly efficient system for reducing the observations, which were printed annually. He also carried on theoretical studies. In 1831 he published in the Transactions

of the Cambridge Philosophical Society an important paper on "The Inequality of Long Period in the Motions of the Earth and Venus." He wrote for the British Association in 1832 a most useful " Report on the Recent Progress of Astronomy," and in 1833 prepared valuable papers on "The Mass of Jupiter."

When Mr. Pond, the sixth Astronomer-Royal, resigned his office in 1835, Lord Auckland, the First Lord of the Admiralty, appointed Prof. Airy to be his successor; and on January 1, 1836, the new Astronomer-Royal entered upon his duties. This was a position which accorded in all respects with Prof. Airy's wishes, and in the course of the long period during which he held it he not only maintained, but greatly increased, the fame of the Royal Observatory at Greenwich as one of the most important centres of astronomical investigation. To him the Royal Observatory owed its equipment with a series of new instruments, all of which were made from his designs, while some were of his own invention. The first of these instruments-the altazimuth-was set up in 1847, the object of the instrument being to secure that observations out of the meridian should be as accurate as observations in the meridian. The erection of this instrument led to results of much importance and interest in the observation of the moon. Other instruments erected were a new meridian-circle, the reflex-zenithtube (put in the place of the Troughton zenith-sector), a new equatorial, an instrument planned to decide the question of the dependence of the measurable amount of sidereal aberration upon the thickness of the glass or other transparent material in the telescope, a doubleimage micrometer, and an orbit-sweeper, designed for the detection of comets approaching perihelion passage, the time of which cannot be exactly fixed.

The observations were made at Greenwich with perfect regularity, reduced most carefully, printed, and placed at the disposal of all who were capable of using them. We need scarcely say that they are of enormous value to

astronomers.

It was

The reduction of the Greenwich lunar and planetary observations from 1750 had been proposed to astronomers by Bessel as a task well worthy of serious effort. undertaken by Airy in 1833, and completed in 1848; and, as we have stated in our previous article, the reductions thus effected serve as the basis of the greater part of our present tables of the motions of the moon and the planets. He reduced various other series of observations, and by his untiring activity stimulated competent students, both in England and elsewhere, to undertake kindred work. He also gladly undertook labours which were in other ways fitted to advance astronomical science. In 1842 he went to Turin to observe the total solar eclipse, and he went for a similar purpose to Gothenburg, in Sweden, in 1851. The eclipse expedition to Spain in 1860 was organized by him, and to his care was intrusted the equipment of the British expedition for observing the transit of Venus in 1874.

Soon after his appointment to the position of Astronomer-Royal, Airy proposed to the Government that magnetical and meteorological observations should be made at Greenwich; and in 1838 his scheme was adopted, the result being that a vast number of data have since been accumulated. We need only refer to such work as his useful experiments on the deviation of the compass in iron ships; his researches on the density of the earth by observations in the Harton Colliery; and his investigations in connection with the standards, the fixing of the breadth of railways, and the introduction of a new system for the sale of gas.

His scientific eminence secured for him the position of President of the Royal Society, which he held from 1871 to 1873. He became a C.B. in 1871, and a K.C.B. in 1872. He was medallist of the French Institute, of the Royal Society (twice), of the Royal Astronomical Society

(twice), and of the Institution of Civil Engineers. The Paris Academy of Sciences made him one of its eight "Associés étrangers," and he was an honorary member of many scientific Societies both at home and abroad.

Among the works of Sir George Airy is a little book entitled "Popular Astronomy," which has passed through many editions. He was also the author of "Treatise on Errors of Observation," "Treatise on Sound," "Treatise on Magnetism"; and of contributions to the "Penny Cyclopædia" and the " Encyclopædia Metropolitana," on such subjects as Gravitation," "Trigonometry," "Figure of the Earth," and "Tides and Waves."

NOTES.

MEN of science were much pleased to learn on New Year's Day that a peerage of the United Kingdom had been conferred on Sir William Thomson. This is the second time Lord Salisbury has done honour to a President of the Royal Society, and on both occasions the wisdom of his action has been very generally appreciated. The work of men like Sir George Stokes and Sir William Thomson brings with it, of course, its own reward; but it is good for the nation that the value of their services should be officially and adequately recognized.

THE following will be the Presidents of Sections at the Edinburgh meeting of the British Association :-Mathematics and Physical Science, Prof. Arthur Schuster; Chemistry and Mineralogy, Prof. Herbert McLeod; Geology, Prof. Charles Lapworth; Geography, Prof. James Geikie; Economic Science and Statistics, the Hon. Sir C. H. Freemantle; Mechanical Science, Prof. W. C. Unwin; Biology, Prof. W. Rutherford; Anthropology, Prof. Alexander Macalister.

THE Institution of Electrical Engineers will hold the first of its meetings during the current year on Thursday, the 14th inst., when the President, Prof. W. E. Ayrton, F. R. S., will deliver his inaugural address.

AT a Congregation held at Cambridge on Monday, the Duke of Devonshire was elected to the Chancellorship of the University, without opposition, in succession to his father. The formal installation will take place in the Easter term.

THE general meeting of the Association for the Improvement of Geometrical Teaching is to be held at University College, Gower Street, on Saturday, January 16. At the morning sitting (11 a.m.), the reports of the Council and the Committees will be read, and the new officers will be elected. After an adjournment at I p.m., members will reassemble for the afternoon sitting (2 p.m.), at which the following papers will be read :-On Laguerre's dictum concerning direction, by Prof. R. W. Genese; on the geometrical interpretation of fallacy in

elimination, by Prof. R. W. Genese; on the use of Horner's

method in schools, by Mr. E. M. Langley. All interested in the objects of the Association are invited to attend.

DR. RICHARD PFEIFFER, the son-in-law and assistant of Prof. Koch, and head of the Scientific Department of the new Royal Institute for Infectious Diseases, has, it is stated, discovered the influenza bacillus. Full particulars are to be pub lished shortly. Meanwhile, according to a Reuter's telegram, it is already known that "six attempts at transplantation of the microbe have been made, and have been attended with complete success, thus proving the genuine character of the discovery." THE International Sanitary Conference met at Venice on Tuesday. This is the sixth occasion on which the Conference has assembled. Its first meeting was held at Paris in 1851. This was followed by gatherings at Constantinople in 1860, at Vienna in 1874, at Washington in 1881, and at Rome in 1885.

by Dr. H. W. Wiley, chief chemist of the Department, in which are shown the chemical composition of maize, and its relative value for food purposes in comparison with other cereals. There is also a chapter, prepared by the assistant statistician, Mr. B. W. Snow, under the direction of the statistician, offering some additional observations as to the possibility of extending the use of this cereal among the people of Europe as a human food, and presenting a number of statistical tables showing the yield and value of the American corn crop.

AN important Bulletin on the forest and mineral wealth of Brazil has lately been issued by the Bureau of the American Republics. The forests of Brazil abound in woods of great value, some of the finest of which are said to be entirely unknown in Europe. With regard to mineral resources, Brazil is not less fortunate. Scientific explorers have found great deposits of coal and iron, and have also proved that the country possesses copper, manganese, and argentiferous lead ore. There are also mines of gold and diamonds. Diamonds are co-extensive with the gold deposits, and, like that metal, are most abundant in Minas Geraes, where they have been found since 1789. The most important locality known for the production of these gems is the district of Diamantina, in the above-named State. They are found in Parana, in the gravels of the River Tibagy, and in the bed of streams dry during the summer. Since the discovery of diamonds at the Cape of Good Hope, the Brazilian production has greatly diminished. As regards iron, the State of Minas Geraes abounds with it. It is not found in veins or strata, buried deep in the earth, but in enormous beds, often lying at the surface, or in mountain masses. These vast deposits are worked only by small scattered furnaces, charcoal being used in the reduction of the ore. Of these small furnaces there are five groups, producing about 3000 tons annually, the product being used in the surrounding districts in the manufacture of articles of home consumption, such as hoes, shovels, picks, drills, nails, horseshoes, &c. In the State of San Paulo are found deposits similar to the best Norwegian ore; and one of the mines is worked by the Government establishment near the village of Sorocaba. This establishment has two furnaces, and produced in one year about 790 tons of pig-iron. The ore has about 67 per cent. of iron. In Santa Caterina, not far from a harbour accessible to the largest vessels, are vast deposits of hæmatite, containing, on an average, 30 per cent. of manganese, and 20 to 30 per cent. of iron. In the State of Goyaz, as in Minas Geraes, are found enormous masses of the ore itaberite. PROF. GEORGE H. WILLIAMS contributes to the latest of the Johns Hopkins University Circulars an interesting account of a geological excursion in Maryland by students of that University in May 1891. The land area of Maryland is approximately 10,000 square miles, which may be in round numbers divided between the three topographically and geologically distinct provinces as follows: (1) Central Maryland, called the Piedmont Plateau, with 3000 square miles between the Catoctin Mountain on the west and a line drawn from Washington to

Wilmington on the east, exhibits a gently rolling country of moderate elevation and relief. This is composed of the most ancient and contorted rocks-highly crystalline toward the east, and semi-crystalline toward the west. (2) Western Maryland, or the Appalachian Mountain province, embracing the 2000 square miles west of Catoctin Mountain. This region is formed of the entire sequence of Palæozoic strata thrown into a series of regular folds or undulations. (3) Eastern and Southern Maryland, belonging to the coastal plain, has about 5000 square miles of undisturbed and unconsolidated strata, in nearly horizontal position, and representing the accumulations from the Jurassic to the present. In the course of each year an effort is made to give students of geology at the Johns Hopkins

University a practical acquaintance with the petrography, palæontology, structure, and topography of each of these three provinces by a series of excursions which are conducted exclusively for this purpose. In the excursion in May the route of the party lay along the section through the Appalachian Mountains exposed by the gorge of the Potomac River.

IN the new number of the Internationales Archiv für Ethnographie there is a learned and well-arranged paper, by C. M. Pleyte, on the use of the sumpitan and bow in Indonesia. A line may be drawn passing over Flores, to the east of Manggarai and Buru, to the west of Halma-Lera, and to the east of the Philippines, exactly marking the limit of the use of the bow. To the east of this line the bow is in general use, while to the west it is found only sporadically. A second line traced westward of Sumba, eastward of Sumbawa, to the south and east of Celebes, and to the east of the Philippines, marks the limit of the use of the sumpitan, which is found nowhere to the east of it. Between these two lines-on the islands of Sumba, West Flores, Saleyer, Buton, Buru, the Sula Islands, the Banggai Archipelago, and the Sangi and Talaut Islands—neither sumpitan nor bow are known. The author points out that these two limits correspond very closely with the line accepted by Dr. Brandes, separating the eastern from the western branch of the Malayo-Polynesian languages. It appears, therefore, that those natives who use the sumpitan form one family in point of language, and that the like is the case with those who use the bow.

the U.S. National Museum two interesting prints of Havesu-pai DR. R. W. SHUFELDT contributes to the Proceedings of Indians. The prints are reproductions of photographs which were taken several years ago by Mr. B. Wittick, formerly a photographer in the employment of the U.S. Geological Survey. The Havesu-pais live in one of the grandest cañons in Arizona, occupying their primitive lodges along the bank of the stream that passes through it. They are a dying race, and very little is known about them. The styles of their lodges are well shown by Dr. Shufeldt's plates, which also display the varied costumes of the men, women, and children, and the peculiar forms of their baskets. The fashion in which the hair of the women and girls is "fixed" seems to point to affinities between the Havesu-pai and the Pueblan Indians.

IN the new number of Insect Life, Dr. C. V. Riley directs attention to what he calls a new herbarium pest. In September 1890, a number of small Geometrid larvæ were found by the botanists of the U.S. Department of Agriculture infesting certain dried plants in the Department herbarium, and especially those which had been received from Mexico and Lower California. The fact that the insect has appeared on dry

plants from the comparatively arid western regions may, Dr. Riley thinks, furnish a clue to its original habit. It would seem possible, if not probable, that it normally feeds on the dead or dry plants of Mexico and adjacent arid regions, and that it has

simply adapted itself to the somewhat similar conditions prevailing in herbaria. It is a new species, and for the present may be placed in the Acidalinæ.

MR. W. VERNER writes to the current number of the Zoologist that the Kentish plover, like the stone curlew, or thickknee, is being rapidly exterminated in the county from which it derives its name, by collectors and so-called "naturalists," who, with walking-stick guns, in and out of season, destroy all they can approach. "These gentry," says Mr. Verner, "do more harm even than they imagine, for I have come across many small plovers and other birds which have been ineffectually 'peppered,' and have gone away to die. Still oftener I have found nests of the ringed and Kentish