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POPULAR SCIENCE MONTHLY. 



and cry. The angular hills and long slopes 

 of talus are not softened by any arborescent 

 veil. The infrequent villages nestle behind 

 sheltering bluffs, and are rarely visible from 

 without the harbors. In winter all the 

 heights are wrapped in snow, and storms of 

 terrific violence drive commerce from the 

 sea about them. Once pass within the har- 

 bors during summer and the repellent fea- 

 tures of the landscape seem to vanish. The 

 mountain sides are clothed with soft yet 

 vivid green, and brilliant with many flowers. 

 The perfume of the spring blossoms is often 

 heavy on the air. The lowlands are shoul- 

 der high with herbage, and the total absence 

 of trees gives to the landscape an individu- 

 ality all its own. No more fascinating pros- 

 pect do I know than a view of the harbor of 

 Unalashka from a hill top on a sunny day, 

 with the curiously irregular, verdant islands 

 set in a sea of celestial blue, the shore lines 

 marked by creamy surf, the ravines by 

 brooks and waterfalls, the occasional depres- 

 sions by small lakes shining in the sun. The 

 sea abounds with fish; the offshore rocks 

 are the resort of sea lions, and formerly of 

 sea otters ; the streams afford the trout- 

 fisher abundant sport, and about their 

 mouths the red salmon leap and play. In 

 October the hillsides offer store of berries, 

 and in all this land there is not a poisonous 

 reptile or dangerous wild animal of any sort. 

 The inhabitants of this land are an interest- 

 ing and peculiar race." 



The Underground Houses of Teehin, Tu- 

 nisia, The curious underground houses of 

 Teehin, and other places near Gabes, in 

 Tunisia, are described by M. Albert Tissan- 

 dier, in La Nature, as being easily cut out of 

 the clay-limestone rock. A square pit, twenty 

 or twenty-five feet deep, is generally dug 

 first to form a central court, from the lower 

 part of which are made the grottoes that 

 serve as sleeping and store rooms. A gently 

 sloping gallery rising from the level of the 

 bottom to the level outside, and closed by a 

 modern door, is the means of communication 

 with the country without, or forms a path to 

 other houses. Niches are cut in the walls 

 of the entrance court for storage of the agri- 

 cultural implements and things of minor 

 value, and silos are provided for the grain 

 crops and oil jars. The rooms are lighted 



only through the doorway from the entrance 

 court. They are furnished with mats and 

 carpets. A bed and a wooden pedestal for 

 the lamp, rudely carved and whitewashed 

 like the walls of the cavern, form the princi- 

 pal ornaments, and a few primitive utensils 

 of enameled earthenware are the principal 

 articles of furniture. The size of the house 

 and the number of rooms, etc., vary accord- 

 ing to the wealth and station of the pro- 

 prietor. 



A Measure for Odors. Very interesting 

 studies have been made by M. Eugene Mes- 

 nard of the perfumes of flowers, valuable to 

 science and to the perfumer's art. This art 

 is still in a rather crude state because it has 

 never found a practicable way of measuring 

 an odor or of determining the strength of the 

 several odors which it may seek to combine. 

 M. Mesnard has observed, however, that 

 though the absolute intensity of an odor can 

 not be measured, its comparative strength 

 can be estimated. A perfumer who has five 

 or six hundred kinds of fragrance in his 

 shop can readily distinguish the differences 

 between them, although he can not tell how 

 strong any of them are. So it is possible to 

 detect by the smell the existence of a large 

 number of chemical substances, although it 

 is impossible to guess how much, if any, of 

 them may be present in the air. Suppose, 

 now, the author says, we pass in a given re- 

 ceiver air charged with a known perfume and 

 air which has passed over a special essence 

 spirits of turpentine, for example. It is 

 possible to obtain in this way a mixture of 

 neutral odor, or such that a very slight vari- 

 ation of its constituents on either side will 

 cause the special odor of the perfume or the 

 smell of the turpentine to prevail. We can in 

 such case regard the two odors as equivalent, 

 and have only to seek a means of determining 

 the intensity of the turpentine odor to have 

 a measure of that of the perfume. A meas- 

 ure for the turpentine is obtained by means 

 of the property which it has of extinguish- 

 ing the phosphorescence of phosphorus. For 

 that purpose a bit of common starch is em- 

 ployed which has been dipped in a sulphide- 

 of-carbon solution of phosphorus. The sul- 

 phide evaporates and the starch remains, a 

 homogeneous substance impregnated with 

 phosphorus which shines in the air. The 



