244 



SCIENCE. 



[Vol. XXII. No. 561 



or in an 3' way corrupt the story it was comraissionecl to 

 tell. A\'hat faith ! But this is little more than the shadow 

 of an illustration ; for Herschell, the astronomer, thought it 

 jirobable that we can see nebuhie from w-hich it has taken 

 light 300 000 years to reach the earth, during which time 

 the interstellar medium has been faithful in transmitting 

 at the rate of more than 11,000,000 miles per minute the 

 impulse committed to it, notwithstanding its path has 

 been crossed and recrossed by other waves without num- 

 ber. Pen cannot adecjuately describe the transcendant 

 j)roperties of this wonderful medium called the "lumine- 

 ferous isther" nor to highly exalt that faith which en- 

 ables one to implicitly believe the truthfulness of the sto- 

 ries committed to him. One is led to exclaim with the 

 Psalmist "Oh Lord ! how manifold are thy works, in wis- 

 dom thou hast made them all." 



CITY BIRDS OF DENVER, COLORADO. 



BY HOKACE G. SMITH, DENVER, COLO. 



Perhaps some of your readers would like to know some- 

 thing of the city birds which come about our dwellings 

 in Denver, Colorado, and wherein they differ from the 

 familiar si^ecies so near to the hearts of the bird lovers 

 who live east of the Mississi23pi River. 



To be sure, many of the Eastern species, whose geogra- 

 phical range is so extensive lind their way, across the 

 (Jreat Plains, to our city at the base of the RockyJMountains, 

 still trvie to the type of their eastern friends, but lor the 

 most part the species undergo a radical change when we 

 enter the high and arid regions of the Great Plains and be- 

 come of a bleached and faded appearance which gives rise 

 to subspecies or varieties; or, as is often the case, a new 

 species takes the place of its eastern relative. 



Among those species which we have in common, the 

 Yellov.' warbler (Dendroica aesliva) is perhaps one of the 

 most familiar summer residents, and its neat little nest is 

 often built in the shade trees along our streets or in the 

 shrubbery of some garden, and its familiar song is heard 

 even in the heat of middaj'. when most birds are silent. 



Scarcely less noticeable is the Kingbird or Bee Martin 

 [Tt/ranmif tijrannun,) the Cliff swallow and the Barn swal- 

 low, whose habits are well known to most readers and 

 may not be detailed here, though I may mention that a 

 pair of Barn swallows has returned to the writer's barn- 

 loft for about fifteen successive years, and when unmoles- 

 ted has reared two broods per season. Their mode of 

 entrance was through an open window, which they usu- 

 ally found shut ujjon their return migration in the spring, 

 but would soon make their presence known by repeated 

 scoldings and fiutterings before the glass and would en- 

 ter and take possession as soon as the window was opened. 

 Hence I suppose it to be the same pair, though the evi- 

 dence is not conclusive. 



Perhaps the most conspicuous of our summer birds is 

 Bullock's oriole, which takes the place of the Baltimore 

 oriole of the east. This brilliant bird is a common breed- 

 er over the entire citj-, wherever trees are found in 

 which to built its swaying nest, and it is not an uncom- 

 mon occurrence to find several nests — which have been 

 built in successive years — in the same tree. 



I hi ve often watched these birds in the earlj' morning, 

 searching for insects in the arc light globes; their method 

 being to enter the globe for any tempting morsel and then 

 flying to the next in line. 



Sjjeaking of the electric lights reminds me of the little 

 House finch {Cm-podacums in frontali») whose song often 

 cheers us in the winter time, when most birds are silent. 

 It would be hard to part with this little bird, for his song 

 is rich and pleasing. Being a resident with us, Ihey rear 

 their young near to our homes, usuallj' in trees or cre- 



vices of building's, but being progressive they have length- 

 ened their breeding season by taking advantage of the 

 heat furnished by the electric lights, by building their 

 nests in the lamp shades above the lights, thus being en- 

 tirely p>rotected from the weather. 



The past summer I was told by one of the trimmers 

 that nearly every light on his beat contained one of these 

 nests. 



Among other summer residents, more or less common 

 I may mention the Western robin. Mountain bluebird. 

 Warbling vireo, White-rumped shrike. Lazuli bunting, - 

 Black-headed groobeak. Western chipjaing sparrow, Ar- 

 kansas goldfinch, western meadow lark. Say's phoebe, 

 western wood pewee. Mocking bird and western King- 

 bird, the latter being a cousin of the Bee martin and hav- 

 ing all the habits of his querulous relative. 



The Pine siskin {SpinuK pinna), though considered a 

 migrant with us, occasionally rears its young here; a pair 

 having built their nest in an evergreen m the writer's yard. 

 This is not so surprising when we consider that its natural 

 summer home among the coniferous forests may be found 

 within fifteen miles of Denver, in the mountains. 



Parkman's House wren ( IVoglodylea cedon parkmanii) 

 seems less familiar than the eastern bird, at least in the 

 manner of its nesting, for, though not uncommon in our 

 city in migration, it seems to retire to the thickets along 

 oiir streams to build its nest; usually taking possession 

 of some crevice or deserted woodpecker's hole. 



A few winter birds remain with us but perhaps none 

 so common or well distributed as the House finch before 

 mentioned. The western Tree sparrow. Mountain chica- 

 dee, Long tailed chicadee, McCown's longspur, Cassin's 

 finch, Harris's and Batchelder's woodpeckers, the Nor- 

 thern shrike and several varieties of Juncos or snowbirds, 

 though the Desert horned lark (Olocoris a. areiiicola) is the 

 familiar "snowbird" of the region and is often seen in 

 numbers in the outside streets, especially when snow is 

 on the ground. 



At other times it is not often noticed though it may be 

 present, for its plumage harmonizes well with its sur- 

 roundings. Besides these we have an occasional visit from 

 the snowfiakes, Red piolls and some others. 



I make no mention of the host of* migrants, which fill 

 our city during the migrations, including rare and cui-- 

 ious species of warblers, sparrows, thrushes, flycatchers 

 etc., nor of other summer residents of the region, whose 

 summer haunts are found in woodlands or ujjon the plains, 

 for this is essentially a paper upon "citj''' birds. These 

 may receive our attention at some future time. 



OVERHEAD SOtNIS IN THE VICINITY OF YEL 

 LOWSTONE LAKE. 



BY EDWIN LISTON, WASHINGTON, PA. 



While engaged in making certain investigations for the 

 United States Fish Commission in the summer of 1890 my 

 attention was called to an interesting phenomenon in the 

 vicinitj' of Yellowstone Lake, of which I am jjleasantly re- 

 minded by the following brief but vivid description in a 

 recent report by Prof. S. A. Forbes. 



Under his descrij)tion of Shohone Lake, Professor 

 Forbes, in a foot note, thus alludes to this phenomenon : 



"Here we first heard, while out on the lake in the bright 

 still morning, the mysterious aerial sound for which this 

 region is noted. It put me in mind of the vibrating clang 

 of a harp lightly ancl rapidly touched high up above the 

 tree toj)S, or the sound of many telegraph wires swinging 

 regularly and rapidly in the wind, or, more rarely, of 

 faintly heard voices answering each other overhead. It 

 begins softlj' in the remote distance, draws rapidly jiear 

 with louder and louder throbs of sound, and dies away in 



