Omaha Daily Bee Newspaper, March 8, 1903, Page 28

Search for Observatory Sites | IN THE ANDES. The Peak of E1 Mieti and the City of Arequipa in Peru, Where American Astronomical Science Has Established Its Southern Outpost % OSTON, March 5.—(Special Corre- spondence of The Bee.)—Mr. Per- cival Lowell, founder and di- rector of the Lowell observatory at Flagstaff, Ariz., and professor of astronomy at the Massachusetts Insti- tute of Technology, to the upbuilding of which the well known Lowell family of this city, of which he is a member, has 80 long and so faithfully contributed, has recently left Boston for Flagstaff to make final arrangements for a unique series of explorations which he is soon to undertake with the idea of seclecting the best pos- sible sites, the world over, for future sstronomical observation, It has always been a serious embarrass- ment that an astronomer in one loeality often makes observations that are appar- ently not in harmony with parallel records made at some other observatory. At pres- ent it is hard to tell how far this sort of disagreement is due to atmospheric con- ditions. In other words, there is no com- mon standard of ‘“‘good seeing,’” as astron- omers call it. But Mr. Lowell, with other &stronomers, holds that there are certain definite optical phenomena from which, after proper comparison and study, such a standard may be evolved—a standard by means of which all obscrvations everywhere can be reduced to a common basis. Mr. Lowell's expedition, therefore, will be practieally an exploration, conducted in both hemispheres, into atmospheric condi- tions—that is, of the air itself, as the medium through which every astronomer must look, however high up in the moun- tains he may climb for a site for his ob- servatory, or however perfect his instru- ments may be, Moreover, Mr. Lowell's problem involves more than just clearness of atmosphere, though this, too, is important. No one, of course, would dream of planting a valuable telescope in the heart of London or Chi- cago. The clearer the air the nearer and sharper seem all distant objects, and stars are no exception to the general rule. Put in a nutshell, the gist of the matter lies In the fact that the air—whether clear or not clear-——is in constant vibration, the de- gree of the vibration varying according to locality. These air vibrations, or air waves, Inevitably affect the appearance of the stars and other heavenly bodies as seen through a telescope or recorded by a eamera. In every tract or space of air, moreover, several separate systems of vi- brations, In each of which the waves are of a regular length, though this length may vary from a fraction of an inch in one system up to several feet in a se~ond or a third, are always to be found inter- playing with one another, Although we are not ordinarily con- scious of them, these restless waves of air affect eur seeing in much the same way as when we open our eyes under water and look up toward the sunlight. The differ- ence is that we are used to being under an ocean of air and we are not used to being under an ocean of water. Under the waler we see the sun as a blur, but so, too, we actually se it through the air. We look out inte space threugh a vibrating medium, and this will be our fate to the end of time. We shall never see the sun, the planets and the fixed stars with ab- solute precision. Fortunately for the ustronomers, there are times and places of relatively *“good seeing.” In these places the general ac- tion of the air waves can be accurately figured out so as to bear a definite rela- tion to the diameter of the object glass of one's telescope., This sounds a little hard, but the principle is really very simple. It an air wave from crest to crest, that is, is shorter than the diameter of the glass, then an inequality of refraction results, which confuses the thing that you are looking at. If, on the other hand, the wave is longer than the diameter of the glass, then the image merely seems to sway back and forth as a whole. Ideally good seeing is neither of these. It is where the wave lengths are practically the same as the * diameter of the glass, and the way to find *out whether the air waves are longer or Unique Astronomical Expedition Undertaken by American Scientists HARVARD OBSERVATORY AT AREQUIPA, PERU. A Near View of a Typical High Altitude Station of the Kind Which Prof. Lowell Has in Mind in His Coming Search for the Best Available Sites. IN JAMAICA. The Temporary Harvard Observatory in Which Prof. W. H. Pickering Pre- pared His New Atlas of the Moon. The Big Telescope Here Shown is Pointed Downward, the Heavens Being Reflected in a Mirror. shorter or approximately just what is wanted for good seeing is merely to select a certain diameter of glass as a standard, by means of which to study thes varying conditions in various localities, the glass itself, of course, being always of the same quality and the same make. This method of determining wave lengths will, of course, be well understood by the men whom Mr. Lowell chooses for (h: work of the coming expedition, although even the amateur can note the phenumenon ap- proximately if he will take out the eye piece of a telescope and place his eye in the focus of the instrument while pointing it as some sufficiently bright object. The air lengths also may be estimated by care- fully noting the charactev of the star's so- called spurious disc and ring as seen through the telescope—that is to say, by the kind of ‘‘dazzle’” which surrounds a star and which anyone may note by looking up into the heavens with the naked eye. In accordance with this latter point each ob- server in Mr. Lowell's expedition will be provided with a standard scale of seeing, originated by Pref. W. H. Pickering of Harvard and worked by Mr, A. BE. Douglass of the Flagstaff observatory, on which the numbers run as follows: 0. Disk and rings of a star in one con- fused mass, violet motion, image greatly enlarged and varying in size. 2. Disk and rings in one confused mass, constant motion no increase in size, 4. Disk well defined, no evidence of rings 6. Disk Well defined, rings broken into lots and lines, but still traceable, 8. Disk well defined, rings complete, but moving. 10. Disk well defined, rings motionless, This scale has been found to give a very satisfactory mode of classifying atmos- pheric conditions as they apply to visual observations In regions where general conditions give comparatively goocd seeing, Nos. 0, 2 and 4 are very readily dis- tinguished. Nos. 4, 6, 8 and 10 are sub- ject to quick transition from one to an- other; but they represent distinctly differ- ent systems of air vibrations, In the work of exploration the Lowell observers will classify the state of the atmosphere of each locality observed for a considerable period of time, and only those places in which a high average is obtafned—an at- mosphere, that is, in which the conditions are best adapted to exact astronomical work—will be considered available for es- tablishing observatories. All probable sites, in other words, are Lo be subjected to a sort of competitive examination, From such data as are already at hand it is beligved that Mr. Lowell's ideal localities will be found, not exactly in deserts, but on the verge of deserts or in oases. The sud- den changes of temperature and the con- sequencent perplexing air currents make the treeless tracts rather undesirable. Similarly, a site on the side of a mountain ravine is generally somewhat exposed to etrong draughts ¢f wind which militate to & greater or less degree against good see- ing. In this regard, the observatory at Flagstaff is very favorably situcted, being sheltered by pine woods, surrounded on every slde by the desert and is very likely typical of the special locations which the Lowell expedition will set out in search of. Among other things, the general adop- tion of an acceptable scale of seeing, to- gether with the selection of a number of definite sites for observations, would prob- ably greatly help the study of the planet Mars, in which Mr. I.owell has for some time been personally much interested. Our knowledge of Mars grows apace from year to year, and the conviction is every year strengthened that our neighboring planet presents a scene of immense and wonder- ful activities. The network of great strips, which are supposed to be lines of verdure along vast irrigation sluices and which ex- tend from the Martian poles to the equator, has already been carefully studied; but given the very best portions of the world to view it from, we may look forward con- fidently to still further results. Of course neither what we have discovered on Mars nor even what we are likely to discover after an agreement among astronomers has been reached as to a scale of seeing is likely to reveal to us the nature of the inhabitants, if such there are. They might be in the shape of beetles or elephants or lizards rather than of human beings. But whatever their physical characteristics, something evidently exists there—just what we shall probably know more about in the future chan we know now. Mr. Lowell's project has grown directly out of the experience of the two leading American high sltitude observatories, the Peruvian station of Harvard university in the Andes, near Arequipa, and the Lowell observatory at Flagstaff. The former was located in 1889 by Prof. Solon Bailey. Its work has been notable in the annals of sclence, for in it was established the great Bruce telescope, mede for Harvard through the generosity of Miss C. U. Bruce of New York, who, in 1889, gave $50,000 to be ap- plied to the construction of a photographic telescope of a special type, and to secure its use under the most favorable climatic conditiors possible. This instrument, made under the direction of Prof. Edward C Pickering, the director of the Harvard ob- servatory, has proved iuvaluable in high altitude astronomy. Much of the work, however, of the Arequipa station has been devoted to a single department ot the science, namely, stellar photography, up- wards of 25,000 photographs of the south- ern sky having been taken there since its erection. Another Harvard tropical obsevatory which may be noted in this connection and which, though not located at a great alti- tude, yet proved itself very useful, was the station which was maintained for a time at Mandeville, Jamaica. Herc Prof. W. H. Pickering made his well known studies of the moon, looking downward into a great mirror through a tele pe 136 feet long. The seeing at this station in the highlands of Jamaica was found to be fairly good, though not equal to that of the Arequipa observatory and presum- ably inferior to that at Flagstaff, The Lowell observatory at Flagstaff was started in the spring of 1804, with the spe- cial object of enabling Mr. Lowell and his assistants to study the planet Mars. Very complete apparatus was installed for this purpose, including an eighteen-inch tele- scope with Brashear lens, a twelve-inch telescope and several smuller portable in- struments. In 1895, also, Alvan Clark & Sons of Cambridge sent to Flagstaff a twenty-four inch telescope, a size now gen- erally recognized as being large enough for all practical purposes. The Flagstaff site is very favorable to good seeing during nine or ten months of the year. It is situated at an elevatien of 7,000 feet and lies ten miles south of the San Francisco mountains, which are about 12,000 feet high. The ob- servatory stands on a ‘‘mesa” or plateau about 350 feet above the town of Flag- staff and looks down in every direction upon a growth of pines. The only objec- tion to the locality is the atmospheric disturbance effected in the winter months through the presence of snow on the neigh- boring mountains, and this difficulty ep- peared at one time so serious that Mr. Lowell started a temporary observatory near the City of Mexico—a fact which is perhaps partly responsible for his present conviction that modern atronomy, with its steadily improving instruments, mut go out and find the best possible place in which to use them, even if the whole world is to be explored to find it, Indians Tried Tobacco Buffalo Bill says that one day in New York he entertained two Indian chiefs at dinper in the Hoffman house cafe. There was a little bottle of tabasco sauce on the table, and the first chief covered his oysters with it, as though it had been catsup. Then he swallowed an oyster, going through strange contortions in the act, though he was too polite to make any outery. His air, though, became sad, and big tears coursed down his cheeks. “Why, brother, do you weep?" the other chief asked, sympathetically, “I am thinking,” said the first, “of my son, Gray Wolf, who was slain in battle.” ‘““Ah,” murmured the second chief, and he, too, covered his oyster plentifully with the fiery sauce, then swallowed one. He, too, in a moment, was shedding tears, His friend said, gravely: “Why do you weep, brother?” “I weep,” was the retort, ‘because I am sorry that you were not slain in that battle you spoke of, along with your son.”— Pittsburg Gazette, The Fresh Drummer When Noah was asked by a fresh drum- mer what time he proposed to make to Ararat he etopped selling tickets a mo- . ment and said: “In about three monuths.” “You're slow,” complained the ques- tioner; ‘“‘on tke overland route they do 13 in two and a half.” “There won't be any other line pretty quick,” sagely replied Noah. *“Its stock is due to be rvatered, and it'll go down. 1} am a monopoly. Better get aboard.” But the foolish drummer had never heard of trusts or Morgan, and perished mis- erably the mnext rainy day.—New York Times.