.7 



/ 



1855.] 



ON THE CLEARNESS OF THE ATiUOSPHERE AT OROOMIAH, IN PERSIA. 



215 



On tile Clearness of tlie Atmosphere tn Oirooiniali) in Fersia> 



BY KEV. T. D. STODDAED.* 



Pi'esuming that a letter written to you from ancient Media, and re- 

 lating to your favorite science, will not be unacceptable, I shall make 

 no apology for the liberty I take in addressing you. My home is in 

 Northern Persia, where I have resided for the last nine years, as an 

 American Missionary to the Nestorian Christians. To give you an idea 

 of our geographical position, I have noted, above, our latitude and 

 approximate longitude. As I msh also to give you a glance at the 

 physical features of this region, let me invite you to come with me 

 upon the flat, terraced roof of my house, where I am sure you will be 

 delighted with the scene before you. Standing at an elevation of 

 more than a mile above the ocean, and a thousand feet above the ad- 

 joining country, you may look down upon one of the lovliest and most 

 fertile plains in all the East. Extending for forty miles in length, and 

 from twelve to fifteen in breadth, the district of Oroomiah smiles with 

 hundreds of villages, is verdant with thousands of orchards, and rows 

 of poplars, willows and sycamores by the water-courses, and in the 

 early summer waves with innumerable fields of golden grain. Here 

 the peach, the nectarine, the apricot, the quince, the cherry, the pear, 

 the apple, and the vine, flourish in luxuriance, and give the appear- 

 ance of a variegated forest. Beyond the plain, you see the lake of 

 Oroomiah, reflecting the purest azure, and studded over with numer- 

 ous islands, while further on rise distant and lofty moimtains, their 

 outlines projected on the cloudless Italian sky, and forming a beautiful 

 contrast with the plain before you. The city of Oroomiah, about sis 

 miles distant, which is so embosomed in trees as almost to be hidden 

 from view, is the probable birth-place of Zoroaster ; and the mounds 

 which are so conspicuous in dilferent parts of the plain, and which are 

 formed entirely of ashes with a scanty soil upon them, are supposed to 

 be the places where the sacred fire was ever kept burning, and the 

 Persian priests bowed in adoration to the rising sun. 



The temperature of this elevated region is very uniform, and the 

 greater part of the year very delightful. Dui'ing the months of June, 

 July, August, September, and sometimes October, there is little rain, 

 and the sky is rarely overcast. Indeed, I may say that often for 

 weeks together not a cloud is to bo seen. As a specimen of the cli- 

 mate in summer, I send accompanying this my meteorological register 

 for the month of August last. The observations were taken at our 

 house on Mt. Seir, but do not diff'er essentially from those taken on 

 the plain at the same season, except that the thermometer is here a 

 few degrees lower, and the air somewhat drier, especially at night. 



No one has ever travelled in this country, without being surprised 

 at the distinctness with which distant objects are to be seen. Moun- 

 tains fifty, sixty, and even a hundred miles off, are projected with 

 great sharpness of outline on the blue sky ; and the snow peak of 

 Ararat, the venerable father of mountains, is just as bright and beau- 

 tiful when two hundred miles distant, as when we stand near its base. 

 This wonderful transparency of the atmosphere frequently deceives the 

 inexperienced traveller ; and the clump of trees indicating a village, 

 which seems to rise only two or three miles before him, he will be often 

 as many hours in reaching. 



In this connection, you will be interested to know that the apparent 

 convergence of the sun's rays, at a point diametrically opposite its disc, 

 ■which, if I mistake not, Sir D. Brewster speaks of as a very rare phe- 

 nomenon, is here so common that not a week passes in summer when 

 the whole sky at sunset is not striped with ribbons, very much like 

 meridians on an artificial globe. 



But it is after nightfall that our sky appears in its highest brilliancy 

 and beauty. Though accustomed to watch the heavens in different parts 

 of the world, I have never seen anything like the splendour of a 

 Persian summer evening. It is not too much to say that, were it not 

 for the interference of the moon, we should have seventy-five nights 

 in the throe summer months, superior for purposes of observation to 

 the very finest nights which favour the astronomer in the New World. 

 When I first came here, I brought with mc a six-feet Newtonian tele- 

 scope, of five inches aperture, of my own manufacture ; and though 

 the mirrors liave since been much tarnished, and the instrument 

 otherwise injured, its performance is incomparably superior to wlintit 

 was in America. Venus sometimes shines with a light so dazzling 



* From a letter addressed 

 Oroomiah, Persia, N. Lat. 37°! 

 T, November 23d, 1852. 



to Sir John F. W. Ilcrschel, dated 

 18' 18", Long. E. from Greenwich 45° 



that at a distance of thirteen feet from the window I have distinguished 

 the hands of a watch, and even the letters of a book. 



Some few months since. Having met with the statement that the 

 satellites of Jupiter had been seen without a glass, by a traveller on 

 Mt. Etna, it occurred to me that I was in the most favom-able circum- 

 stances possible for testing the power of the unassisted eye, and I deter- 

 mined at once to make some experiments on the subject. 5Iy attention 

 was, of course, first turned to Jupiter, but for a considerable time, 

 with no success. It was always so bright, and shot out so many rays, 

 that it seemed quite impossible to detect any of its moons, even at their 

 greatest elongation from the planet. I varied the experiment in several 

 ways, by looking through the tube of a small telescope, from which 

 tlie lenses had been taken, and also by placing my eye near the corner 

 of a building, so as to cut off the most brilliant rays of the planet, 

 and yet leave the view unobstructed to the right hand or the left ; but in 

 neither cases could I find .any satellite. Some time after, I was sit- 

 ting on the teri'ace as daylight was fading into darkness, and thought 

 I would watch Jupiter from its irrst distinct appearance, till it shone 

 out in its full splendour. This time I was exceedingly gratified, just 

 as stars of the first and second magnitude were beginning to appear, to 

 see two extremely faint points of light near the planet, which I felt 

 sure were satelites. On pointing my telescope towards them, my first 

 impressions were confirmed, and I almost leaped for joy at my suc- 

 cess. Since that night, I have many times, at the same hour of the 

 evening had a similar view of these telescopic objects, and think I can 

 not be mistaken as to the fact of their visibility. I must, however, 

 add that none of my associates, who at my request have attended to 

 the subjet, are sure that they detect them, though the most sharp- 

 sighted individual feels some confidence that he can do so. As these 

 friends, however, are not practical observers, their failure to see the 

 satellites does not shake at all my belief that I have seen them myself. 



The time during which these satellites are visible is hardly more 

 than ten minutes. The planet itself soon becomes so bright that they 

 are lost in its rays. I will not stop to discuss the question, in itself a 

 most interesting one, why they are visible at all, when stars of the 

 third and fourth magnitudes are not distinguishable, but merely give 

 you the facts in the case, knowing that you will reason on them much 

 better than I can. Both the fixed stars and the planets shine here with 

 a beautifully steady light, and there is very little twinkling when they 

 are forty degrees above the horizon. 



Having come to a satisfactory conclusion about the satellites of 

 Jupiter, I turned next to Saturn. This planet rose so late in the night 

 that I had not seen it while watching Jupiter, and I was curious to 

 know whether any traces of a ring could be detected by the naked eye. 

 To my surprise and delight, the moment I fixed my eye steadily upon 

 it, the elongation was very apparent, not like the satellites of Jupiter, 

 at first suspected, guessed at, and then clearly discernible, but such a 

 view as was most convincing, and made me wonder that I had never 

 made the discovery before. I can only account for it from the fact 

 that, though I have looked at the planet here with the telescope many 

 times, I have never scrutinized it carefully with the naked eye. Seve- 

 ral of my associates, whose attention I have since called to the planet, 

 at once told me in which direction the longer axis of the ring lay, and 

 that too without any previous knowledge of its position, or acquaint- 

 ance with each other's opinion. This is very satisfactory to me, as in- 

 dependent collateral testimony. 



I have somewhere seen it stated, that in ancient works on astronomy, 

 written long before the discovery of the telescope, Saturn is represent- 

 ed as of an oblong shape, and that it has puzzled astronomers much to 

 account for it. Am I not correct in this impression ? and, if so, is it 

 not possible that here, on these elevated and ancient plains, where 

 shepherds thousands of years ago watched their flocks by night, and 

 studied the wonders of the glorious canopy over their heads, I have 

 found a solution of the qTicstion ? 



After examining Saturn, I turned to Venus. The most I could deter- 

 mine with my naked eye, was, that it shot out rays unequally, and 

 appeared not to bo round ; but, on taking a dark glass, of just the 

 right opacity, 1 saw the planet as a very minute, but beautifully de- 

 fined, crescent. To guard against deception, I turned tlic glass in 

 different ways, and uj^ed different glasses, and always with the same 

 pleasing result. It may be that Venus can be seen thus in England, 

 and elsewhere, but I have never heard of the experiment being tried. 



Let me say here, that I find the naked eye .superior for these pur- 

 poses to a telescope formed of spectacle glasses, of six or eight rosgni- 

 fying power. This is not, perhaps, very wonderful, considering tliat 



