146 



SCIENTIFIC NEWS. 



[Feb. 17, 1888. 



workers are deserving of all praise for their disinterested 

 and untiring efforts. 



James Watt Anniversary Dinner. — At this 

 annual commemoration, held under the auspices 

 of the Glasgow Philosophical Society, and the Scottish 

 Institution of Engineers and Shipbuilders, Mr. 

 John Turnbull proposed " The Memory of James 

 Watt," in an interesting speech, in which the achieve- 

 ments of the great engineer were placed in the clearest 

 light, and some facts were brought forward which 

 have escaped general notice. At an early date, he had 

 conceived the idea of the screw-propeller, which he de- 

 scribed as a "spiral oar." In 177S, he invented the 

 letter copying-press now in common use. In 1783, he 

 was urging the adoption of a decimal system of weights 

 and measures, and in the same year he is described as 

 sending to the Royal Society his theory of the composi- 

 tion of water, " which hypothesis Cavendish afterwards 

 verified by his able experiments." As late as 1811, 

 when in his seventy-sixth year, he perfected a machine 

 for copying statuary, which he used himself with no 

 small success. As far as the principal parts of the 

 steam-engine are concerned, Watt left but little to be 

 done by his successors. 



SCIENTIFIC TABLE TALK. 



By W. Mattieu Williams, F.R.A.S., F.C.S. 

 The geological record gives very decided precedence to 

 marine animals. When a student in Prof. Jamieson's 

 class at the Edinburgh University I was taught that land 

 animals made their earliest appearance in the " car- 

 boniferous system," then classed in the " secondary 

 strata." This excluded the existence of land animals 

 from all that vast period during which the great masses 

 of Laurentian, Silurian, and Devonian rocks were 

 deposited. More recent discoveries prove the exist- 

 ence of land animals earlier than the Devonian, even 

 so far back as the lower Silurian. The discovery of a 

 fossil scorpion there proves more than its own existence, 

 if, like modern scorpions and other spiders, its habits 

 were carnivorous. Such remains of land animals in and 

 below the Devonian rocks are, however, so very rare 

 and exceptional that the geological census represents our 

 earth as a world of waters teeming with animal life, 

 while its dry land was a sterile and nearly lifeless desert. 



These facts are suggestive of many reflections and 

 some queries, the first being whether the geological 

 record really does afford a fair general view of the his- 

 tory of life on the earth. My own opinion is that it 

 does so, as regards shelly and bony marine life, and 

 approximately as regards the shelly and bony fresh- 

 water life, but not so as regards anj' class of the in- 

 habitants of dry land. Most geologists admit this, but 

 the general impression conveyed by their works to 

 general readers is different. 



We must not forget that the geologist only obtains 

 fossil specimens of animals that have been drowned, or 

 buried, or have died in caves. Taking the life-history 

 and death-history of the animals that now exist on the 

 earth, and excluding the agency of man, how many are 



there of those daily dying around us whose remains are 

 thus preserved ? 



The stratified rocks in which fossils are found have 

 been, with a very few rare exceptions, deposited under 

 water, and whatever they contain must therefore have 

 got into the water in order to be there. The manner in 

 which the deposited material of these rocks has reached 

 the water must not be forgotten. It came there by dis- 

 integrating violence of some kind, by "denudation," a 

 wearing away by weathering, flood-washing, wave- 

 breaking, or glacier-grinding. All such agencies capable 

 of tearing up and carrying down to the sea the solid 

 material of the land must have been very destructive to 

 any remains of life that may have laid upon it, or even 

 have been buried beneath it. 



We should also understand that the further we go 

 back in the geological record, the more destructive to 

 possible organic remains must have been the denuding, 

 and down-drifting agencies. Thus the denudation of 

 the dry land of the Laurentian period supplied mate- 

 rial for the deposition of rocks of the Silurian ; that of the 

 Silurian, in like manner, afforded by its demolition, 

 material for the Devonian ; and so on. Each of these 

 great divisions include a large number of subdivisions, 

 in each of which these denudations and re-depositions 

 have been repeated. Thus a given block of new red 

 sandstone may contain grains of sand that have been sub- 

 jected to twenty-fold grindings, and all its associated 

 organic material correspondingly pulverised and oblite- 

 rated. A multitude of monsters might have lived on 

 the dry land when the Oldhamia flourished in the Silu- 

 rian seas, and yet not a bone or tooth of any one of them 

 be ever known to man. 



There is another possibility that has been argued aa 

 impossible, not by geologists or any others of scientific 

 authority, but by theological disputants. The possibility 

 of a general deluge has been denied on the assumption 

 that there is not sufficient water on the globe to cover 

 the land. This of course is true, if the levels con- 

 tinue unaltered, but a little examination shows that 

 only a moderate disturbance would be sufficient to 

 submerge all the plains and fertile valleys, and leave 

 nothing more above the ocean than insular peaks ot 

 barren rock. 



In last January's number of the Scottish Geographical 

 Magazine, Mr. John Murray publishes the results of long 

 investigation of this subject. He estimates the bulk of 

 the dry land above the sea is 23,450,000 cubic miles,, 

 while that of the waters of the ocean is 323,800,000 cubic 

 miles, or between thirteen and fourteen times as much 

 as that of the dry land. There is enough water in the 

 sea to cover the whole of the globe with a depth of two 

 miles if the land were levelled. 



Seeing how greatly the levels of land and sea have 

 varied (I have picked up marine fossils on Mount Pilatus 

 at 7,000 feet above sea level), it is not only possible, but 

 very probable, that during some geological periods there 

 was very little dry land at all on our globe, and the 

 further we go back the greater is the probability that 

 such dry land was but barren rock, seeing that our fertile 

 soils are the products of repeated disintegrations and re- 

 depositions of rock matter. 



America is a very tall country. They have big things 

 of all kinds over there. Among them is a very big 

 glacier in Alaska. The ice is 5,000 feet wide and 700 feet 

 thick where it enters the Muir Inlet (59° N. lat., 136* 

 40' W. long.), and according to Mr.G. F.Wright it advances 



