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THE POPULAR SCIENCE MONTHLY. 



kinds of artifices in order to acquire speed 

 prior to flapping their wings : some run on 

 the ground before darting into the air, or 

 dart rapidly in the direction they wish to 

 take in flying; others let themselves fall 

 from a height with extended wings, and 

 glide in the air with accelerated speed be- 

 fore flapping their wings ; all turn their bill 

 to the wind at the moment of starting." 



Origin of Warts on Forest Trees. The 



formation of abnormal growths knots or 

 warts on forest trees, which are very com- 

 mon on some species, is thus accounted for 

 by Robert Cowpar in Science Gossip : " They 

 are not due to insects, fungus, or accident, 

 but are perfectly natural. Neither may they 

 be taken as indications of health or disease, 

 nor are they in any way attributable to any 

 particular soil or situation. ... In the 

 barks of our forest trees are contained a 

 multitude of latent buds which are devel- 

 oped and grow under certain favorable con- 

 ditions. Some trees possess this property 

 in a remarkable degree, and often, when the 

 other parts are killed down by frost in se- 

 vere winters, the property of pushing out 

 these latent buds into growth preserves the 

 life of the plant. These buds, having once 

 begun to grow, adhere to the woody layer at 

 their base, and push out their points through 

 the bark toward the light. The buds then 

 unfold and develop leaves, which elaborate 

 the sap carried up the small shoot. Once 

 elaborated, it descends by the bark, when it 

 reaches the base or inner bark. Here it 

 is arrested, so to speak, and deposited be- 

 tween the outside and inner layer of bark, as 

 can be learned on examining specimens on 

 trees in the woods almost anywhere." 



Yalne of Phcnological Observations. 



Phenological observations of plants, or ob- 

 servations of the time of the first appearance 

 in the year of the several stages of growth, 

 have long been recognized as useful in the 

 study of climates. A phenological observer 

 may in five years determine approximative 

 means for judging of the succession of 

 each of the phases of vegetation. When 

 we have ascertained the mean time of the 

 occurrence of the principal changes for five 

 years, as, for instance, when the first apple 

 blossoms open in the immediate vicinity of 



the station, or the first fields of barley are 

 cut, we are then able to judge how the sta- 

 tion comports itself relatively to any other 

 station of which the phenological position is 

 fixed ; and how each point of a region com- 

 ports itself relatively to the principal point 

 whether it is colder or warmer. This is 

 determined by the stage of vegetation which 

 the same plants have reached here and there. 

 The method is really more exact than that 

 of establishing hundreds of thermometers 

 and pluviometers at as many different places 

 aside from the trouble and expense of 

 keeping up the observations of so many in- 

 struments. Phenology goes on without ex- 

 pense, while meteorology is costly. We are 

 able, every year and every week in the year, 

 to compare observations of vegetation with 

 means that have been established, and as- 

 sure ourselves whether the vegetation at our 

 station is normal or in advance. Phenology 

 is a kind of thermometry that can also be 

 used to test thermometrical observations and 

 correct erroneous conclusions from them. 

 The plant is a sort of registering thermome- 

 ter. It, in fact, shows us the present condi- 

 tion, as the thermometer does, and likewise 

 all the conditions of the past time, immedi- 

 ately summed up in a final result, while the 

 thermometer simply gives us the daily oscil- 

 lations and leaves us to make the summing 

 up. Phenological observations, with figures 

 founded on comparisons, have the advantage 

 of raising the thought of relation in the mind, 

 of representing something tangible to it. 



Ancient Fireplaces on the Ohio. The 



ancient fireplaces at Blue Banks and other 

 places on the Ohio Biver near Portsmouth 

 are described by Mr. T. H. Lewis as being of 

 three different classes. Those on the lower 

 levels only show a burned streak of clay 

 from five to eight feet in diameter, with but 

 a slight concavity, on which are found ashes, 

 charcoal, burned stones, and bones, with an 

 occasional fragment of pottery, composed of 

 broken stone and clay. Many of them, at 

 the level of twenty feet from the surface, 

 where they are most numerous, are from one 

 to three <eet deep, and are lined with flat 

 stones. The clay outside of the stones bears 

 evidence of intense heat. In some instances 

 they are nearly filled with ashes and char- 

 coal. The pottery within them is composed 



