a black crown. You may hear his interesting song in May or June, and his characteristic catlike call at any time. His song is like that of the robin, thrush and several others jumbled together, with an occasional rasping squawk that detracts somewhat from its beauty. Catbirds have at times perched on branches within a few feet of me in Prospect Park, and sung their rather lengthy ditty, fully conscious of my attention. Kingbirds are plentiful in the country parts, and can be found in our parks domineering over other birds. I have seen a kingbird drive a group of hawks, birds many times larger than himself. The bright little goldfinch, who is only about five inches long, will be recognized by his golden yellow body and black wings, crown and tail. Watch his undulating flight, like a trip on a series of toboggan tracks-working and singing on the up grade, coasting silently on the down grade with wings and feet tight to the body. When at rest he may warble for you like a canary, but his song in flight, which sounds at first as though made up of two notes, will be found to contain six if noted at short range. If watchful, you may surprise him some morning at his bath by a springside, and if you do not approach him too close he will continue the business on hand and leave you in no doubt as to why he is always so spick and span. The yellow warbler, indigo bunting and chickadee are all small birds, about five inches in length. The yellow warbler shows various shades of yellow-golden on the head, greenish on the back, brownish on wings and tail, and the under parts gol den with brownish streaks The indigo bunt ing is a beautiful little ellow, dark blue all over. He has a song with a you persevere until the end of May you will probably meet the Baltimore oriole and cedar waxwing, and may possibly be favored with a sight of the scarlet tanager and rose-breasted grosbeak. The Baltimore oriole-sometimes called the firebird-is about seven and a half or eight inches long, and of beautiful appearance, his upper parts being mostly black and under parts mostly brilliant orange. The cedar waxwing is a very genteel looking A CHICKADEE FAMILY From Chapman's Bird Studies with a Camera more Photographed by author distinct melody than most bird songs, which he sings from the top of whatever he may perch upon, be it bush, tree or house. The chickadee has a black cap and throat, is always busy, never fearful of man, and by his chick-a-dee-dee-dee you will know him at once. Mr. Chapman, in his "Bird Studies with a Camera," gives an interesting account of his discovery of an unusually large family of young chickadees in Englewood, N. J., which he succeeded in photographing after posing them on an improvised perch. You will find that even after a short experience you have acquired a noticeable increase in power to distinguish songs, calls and markings; and should Copyright by Frank M. Chapman resident about seven inches long, upper parts cinnamon shading down to ash, a crested head, two or three wing quills with waxy red tips, and a dark tail with a yellow band on the end which will surely establish his identity. The gorgeous scarlet tanager is a little larger than the cedar waxwing, has red body and black wings and tail, and presents a most beautiful picture against a background of green foliage. I have seen an unusually fine specimen at times about the Vale of Cashmere in Prospect Park. The rose-breasted grosbeak is about eight inches long, and is easily distinguished by the large rose colored spot below his black throat. His upper parts are generally black, with some white spots on wings and tail, and under parts generally white, with rose spots under the shoul ders. He is not very numerous about here, but may come into view at any moment he may be quietly perching above you without giving any indication of his presence, for he is rather reserved in manner. Further attempts to describe the birds that will attract your attention are left to the bird books, as many wil require detailed description. You will surely hear something from the thrushes and warblers, though you may not get close enough to distinguish the several varieties, and the little redstart, the bobolink, the black and white creeper, the white breasted nuthatch, who spends so much of his time upside down, and many others may be among your friends before you have been long engaged in this most delightful of outdoor occupations. ELEMENTARY SCIENCE-SIXTH YEAR, SECOND SAMUEL HOFFMAN, Instructor P. S. 23, Manhattan ELEMENTARY TREATMENT. Pupils completing the sixth school year are not college students. Therefore this subject must be made as simple and interesting as possible. On this account it is better not to tax the children's memories with learning the names of many rocks. They may remain in blissful ignorance of all but the most common kind. rion, as the one who had merely memorized the catalogue, there is no doubt that the method requiring only the name of a rock is not the correct The writer knows of a college graduate who correctly named every rock on examination day only through his having memorized the names corresponding to every number pasted on the rocks. He rightly had assumed that the professor would not present new specimens or re-label the rocks. Nearly all the other students remained session after session, read each rock's number, found its name on their mimeographed papers, drew sketches after some names, tried to discover relations between the name and the specimen, noted its colors, weight, hardness, etc. Though many of these students were not as successful, taking marks as a crite one. In a 6B class all suitable rocks should be handled by the children. The specimens necessarily being limited will have to pass from hand to hand. "The busy whisper circling round" ought not to count against discipline. discipline. Compare the hardness with glass by some one scratching on the window pane (as does the glazier when cutting glass), or on any other rectangular piece of glass. The name which really embraces a summary of all their observations, like definitions, should then be given as a conclusion. There is no dearth of material. Rocks are seen everywhere. It is easy for all to make a private collection. ACTION OF WEATHER AND WATER Known to Unknown.-To gain new knowledge we proceed from the known. The carrying of mud by water flowing into sewers may be seen after every rain. The weathering of rocks may be noticed on window sills and nearly all brownstone houses. Supplementing this knowledge of daily phenomena with pictures found in the geography, we may gain, by reasoning, information of distant places. For example, ask this question: Has the Amazon River a rocky bottom at its mouth? giving reasons for your answer. Not one of us has ever been there, yet it is possible for us to arrive at conclusions. The river flows down hill like the rain water flowing into the sewer. Light things in the street current will be carried along. Stones will remain behind except when the current is swift. Likewise in the Amazon stones may be rolled along. When these roll along in this very long river the possibilities for collisions are enormous. Thus there is a very slight chance of these rocks retaining their original size. Before they will have reached their destination they will have dwindled down to sand or mud. We find an island near the mouth of the Amazon. It is safe to conclude that its soil is increased by deposits of sediment that were transported from above, from the Andes Mountains. We find sandy beaches at popular summer resorts. This sand is near the ocean, where our rivers empty. On account of this pilots are taken on board incoming steamers below Sandy Hook to steer vessels safely into port, because vessels may be stranded on sand bars in the shallow water. The pilot knows the various depths. Buoys, lighthouses and charts are his guides. The Mississippi is also choked at its mouth with mud. We call this soil a delta. Call attention to the name Missouri, which means muddy. Why is it muddy? The Nile and other rivers show similar deposits. PHYSICS AND PHYSICAL GEOGRAPHY. A little knowledge of physics and physical geography will assist us immensely. In fact, the physical geography can hardly be separated from the geology as seems to be done in the course of study. We say that gravitation causes water to flow down hill; that things left unsupported fall to the ground. Did you ever stop to think what the word "ground" meant? Soil is crumbled. or ground up rock, from which most plant life derives its sustenance. Water touching a heated lampchimney will crack the glass. The too rapid heating of a cold lamp chimney or gas globe will have a similar result. This is due to the fact that heat expands things and cold contracts. When this change is not uniformly made damage may follow. Stones are heated by the sun and chilled by rain, hail, or dew. These changes cause rocks to split and gravitation is always a constant force. The Obelisk in Central Park is a familiar illustration of the effect that a change of climate has on rocks. THERMOMETER. The measure of this expansion by heat and contraction by cold is observed in every class room whenever the Fahrenheit themometer is read. We see the mercury rise or fall in the tube with the increasing or decreasing heat. When it falls to the point marked 32 degrees water will freeze. Water, an exception to the rule, expands when it freezes. A bottle filled with water and corked will break when the ice formed therein takes up more space. In the same way water freezing in the cracks of rocks may split them farther asunder. On account of these agencies, gravitation and weathering, we find many stones at the foot of hills. TALUS. Sailing up the Hudson, we often see the bare Palisades, consisting of trap, an igneous rock. At the foot we see grass covered rocks. Their position has been assumed to correspond with the ankle to the foot. Such accumulations of rocky fragments are called talus, which is a Latin word, meaning ankle. STUDY OF SOILS. Soils. On a sandy beach, after the wave recedes, the place seems to become immediately dry again. In clayey soil the water seems to rest as if that soil were a sponge. This may be observed in any open lot. Such ground will not become dry until this water evaporates, flows off, or sinks into the ground, making underground streams. Many have seen logs driven into wet soil so that buildings such as our "sky scrapers" may have a securer foundation. The roots of grass and trees will help to keep water in storage and thus help to prevent floods. Soil that is favorable to the growth of plants is fertile. The fertility of the Great Central Plain of North America is ascribed to the origin of its overlying soil. Geologists tell us that this plain was once entirely under water. Geologists Soils are classed according to their composition as loamy (alluvial-consisting mostly of sand and clay), clayey, sandy, chalky and peaty (soil formed by the decay of vegetable matter). STUDY OF CAVES. Nature study shows us that we may find "tongues in trees, books in the running brooks, sermons in stones." Caves.-Hard rock better withstands the attacks of weather, water and ice, earth's great sculptors. Soft limestone rock is more easily worn down or eaten away by water, especially if it contains acid in solution. The Mammoth Cave of Kentucky was thus formed by underground streams. Water passing over limestone and percolating through any cracks in the roof of a cave will deposit its lime on the floor of the cave, the water evaporating. Such deposits are called stalagmites. Should the drops. of lime water evaporate before dropping to the floor, conical deposits of limestone, stalactites, will eventually depend from the roof. Pictures of stalactites will resemble icicles, for these are similarly formed if we substitute freezing for evaporating. A natural bridge is made by the attacks of water as is a cave. If the roof should also disintegrate or be cut through nothing will remain but the walls, making a gorge, or canyon. Pictures of the Natural Bridge of Virginia, the Hudson River and Niagara River Gorges and the Grand Canyon of Colorado will serve as illustrations. STUDY OF GLACIERS. Glaciers.-Stereopticon pictures of glaciers, icebergs, etc., may be seen in various places by adults at public lectures. Most of our teaching about distant places must necessarily be made on information and belief. A river of ice slowly descending a mountain side carries boulders with it. When the ice melts these stones are dropped, making a a moraine. These rocks, in being moved by the ice, may act as a file and scratch, groove or polish underlying rocks or scoop out lakes. The "Rocking Stone" in Bronx Park and the under |