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THE POPULAR SCIENCE MONTHLY. 



near Quedlinburg belonged to the unicorn 

 of the Bible. Because the Bible assigned 

 extremely long terms of life to the antedilu- 

 vian patriarchs, popular belief ascribed a 

 gigantic size to the ancestors of the present 

 human race ; and parts of huge fossil skele- 

 tons were occasionally preserved in the 

 churches as relics. Such a belief was al- 

 ready so extensive, even in the time of 

 Empedocles, n. c. 450, that a mass of hip- 

 popotamus - bones found in Sicily was de- 

 clared by the learned of the day to be the 

 remains of the giants who fought against 

 the gods. The Mohammedans believed that 

 Adam was as tall as a palm-tree, or about 

 sixty feet, and found a mound of corre- 

 sponding size in Syria to answer for his 

 grave. The academician, Henrien, in 1718, 

 described Adam as thirty-eight and a half 

 metres and Eve as thirty-seven metres high, 

 and herein did not greatly disagree -with St. 

 Augustine. The former world was long be- 

 lieved to have been constructed on a much 

 more gigantic scale than the present ; and 

 the opinion that the old order of things and 

 organisms was vastly different from the ex- 

 isting one, and was subverted by a tremen- 

 dous revolution, prevailed quite generally, 

 till Lamarck and Cuvier pointed out the 

 way to a more consistent theory. 



Defective Hearing in Sehool-Childrcn. 



Dr. Gelle, a French physician, has recently 

 published an important paper on defects of 

 hearing among school-children. Dr. Weil, 

 of Stuttgart, a year or two ago expressed the 

 opinion that about thirty per cent of the chil- 

 dren in commercial schools, and ten per cent 

 of well-to-do school children, hear but im- 

 perfectly. Dr. Gelle, from the examination 

 of fourteen hundred cases of deafness in 

 schools, fixes the proportion of children thus 

 affected at about twenty or twenty-five per 

 cent of the whole number. The deficiency 

 is most obvious in the case of the consonant- 

 sounds, the very ones most essential to the 

 understanding of what is said. Dr. Gelle 

 observes that the range of hearing for a giv- 

 en sound diminishes outside the class-room, 

 or even in a covered yard ; that mistakes 

 -cease or diminish as the distance of the 

 teacher from the pupil is lessened ; and that 

 deafness increases with age. To make the 

 -conditions convenient for the hearing of the 



pupil, the teacher should take pains to place 

 himself in the most favorable position and 

 to articulate distinctly, and the size of the 

 class-room should be adjusted according 

 to the laws which limit the range of the 

 most distinct hearing to about twenty-three 

 or twenty-seven feet. The scholars, having 

 been previously examined with reference to 

 their hearing, should be arranged so as to 

 place those most deficient in this respect 

 nearest to the teacher. 



Significance of the Aboriginal Mounds. 

 In the discussions of the Anthropologi- 

 cal Section of the American Association, re- 

 specting the mounds, Dr. S. D. Peet divided 

 those structures into five classes, as follows: 

 1. Emblematic mounds, built by hunters 

 who worshiped animals. 2. Burial-mounds, 

 a class mostly represented in Michigan, Illi- 

 nois, and Minnesota. 3. Mounds which are 

 probably the remains of the stockades of 

 an agricultural people. 4. Village mounds 

 the remains of villages, and their high 

 places for worship. 5. The peculiar mounds 

 of the Pueblos and Aztecs. The emblematic 

 mounds, having the forms of animals hunt- 

 ed, served a useful as well as a religious 

 I purpose, and were used as screens from be- 

 hind which to shoot the animals that would 

 pass along the game-drives between them. 

 Of their religious significance, Dr. Peet's 

 theory is, that the animals were supposed 

 to be scattered about to guard the central 

 sacrifice or altar mound. He has been led 

 to this belief by observing that the altar- 

 mounds are nearly always situated on high 

 ground, overlooking a river, while the em- 

 blematic mounds are so disposed around the 

 altar-mounds as to suggest the notion of 

 guarding the latter. 



The Singing-Sands of Manchester, Mas- 

 sachusetts. A. A. Julien and Dr. H. C. 

 Bolton presented a paper to the American 

 Association, on the sands of the singing- 

 beach, at Manchester, Massachusetts. On 

 the beach, fcldspathic rocks are intersected 

 by numerous dikes of igneous rocks. The 

 sonorous phenomenon is confined to par- 

 ticular parts of the sand, and is exhibited 

 in areas to which closely contiguous ones 

 arc silent. The sound is produced by press- 

 ure, and may be likened to a subdued 



