PRIZE QUESTIONS OF SCIENTIFIC SOCIETIES. 445 



that the other vertebrata of these islands, especially those of Borneo, 

 of Celebes, and of the Moluccas, and, above all, those of New Guinea, 

 should be submitted to a similar examination. It will award its gold 

 medal to the naturalist who shall send it, either the description of any 

 new species of mammifers, of birds, or of reptiles of those islands, or 

 a memoir containing new and remarkable facts on the structure and 

 habits of some of those animals. 



17. It is desirable to have as exact a determination as possible 

 of the errors of the tables of the moon, which we owe to M. Hansen, 

 by the occultations of the Pleiades, observed during the last revolu- 

 tion of the node of the lunar orbit. 



18. The celebrated mechanist, RuhmkorfF, has obtained sparks 

 of an extraordinary length by the apparatus of induction which bears 

 his name. The society desires to have the laws which govern the 

 length and intensity of these sparks in iiistruments of different size and 

 construction determined by theoretical and experimental researches. 



19. What difference is there between the perception of sounds 

 with one and with two ears ? The society invites precise researches 

 on this difference, and in general on the influence of duality in the 

 organ of hearing. 



20. According to the researches of Pasteur, and other savans, 

 fermentation is due to the development of cryptogams, and of in- 

 fusoria. The society desires on this subject new and positive re- 

 searches, and, to such an extent as may be practicable, an exact 

 description of these plants and animals, and of their mode of action. 



21. What is the best construction and the best method of em- 

 ploying steamboats intended to clear rivers of the accumulations of 

 ice which obstruct their flow of water? It is desired that in answer- 

 ing this question a particular account should be given of all that has 

 been practically determined on the subject, as well in our own country 

 as elsewhere. 



22. Electric perturbations in the atmosphere give rise to electric 

 currents in the wdres of telegraphs. Notwithstanding all that modern 

 researches have made known, these phenomena are not yet completely 

 understood; the society desires that the results of multiplied obser- 

 vations should be communicated to it with an exposition of the most 

 remarkable consequences deducible therefrom on the currents in 

 question, and their modifications agreeably to the different causes 

 which give rise to them. 



23. With the exception of some deposits on the eastern frontier 

 of the kingdom of the Netherlands, the geological formations covered 

 by the deposits of alluvium and diluvium in that country are as yet 

 but very little known. We would be gratified at receiving a state- 

 ment of all which has become known with certainty, whether from 

 the excavations executed in different places or from other means of 

 observation, on the nature of those deposits. 



24. It is known, chiefly by the labors of Professor Roemer, at 

 Breslau, that many of the fossils found near Groningen belong to the 

 same species W'ith those found in the silurian deposits of the island of 

 Gothland. This fact has led M. Roemer to the conclusion that the 

 diluvium of Groningfen has "been transported from this island of 



