108 



SCIENCE. 



[Vol. I., No. 4. 



within one-tentli of one per cent with those of Lie- 

 big: in soft woods the liydrogen is almost tlie same 

 as' in hard, but tlie carl)on is from 4 to 5% greater, 

 giving pine a liiglier fuel-value than hard wood. In 

 these values we find mountain maiiogany at the top 

 (on account of its weight) ; the southern long-leaved 

 pine is next, and at the bottom is poplar; shell-bark 

 hickory is third on the list, these three having 49 to 

 54% of carbon. The pines are very close together, 

 with over 52% of carbon, while the hard woods aver- 

 age a little under 49% of tlie average fuel-value by 

 weight for soft wood : burning one kilo gives 4,488 

 units of heat; hard wood, 3,993.9: by volume, soft, 

 2,524; hard, 2,170. 



In the tests for breaking-strength, the coefficient 

 of elasticity was calculated for all sticks for the first 

 tv/o deflections, i.e., at loads of .50 and 100 kilos, and 

 that at 100 kilos was found in many cases to be larger 

 than that- at the lesser load; but the explanation is 

 found in the fact that there is more or less twist in 

 the stick, no matter how carefully it is dressed; and 

 this twist is increased by seasoning. The first load 

 of 50 kilos is just about sufficient to take out the 

 twist, and the second represents the true deflection. 

 The results have shown, that it is by no means neces- 

 sary to break two sticks to show which is the stronger, 

 provided they are of the same kind of wood : the 

 weak stick will show the largest deflection from the 

 start. The strongest stick found was a piece of 

 common yellow locust, the average of eight or nine 

 specimens giving a breaking-weight of 543 kilos; 

 hickory and southern pine follow closely; ash was 

 found to stand very well up to a certain point, and 

 then it gives way suddenly and without warning, 

 generally shattering badly ; California red-wood shat- 

 ters thoroughly when it breaks, and shows the effect 

 all over, i-endering the entire stick worthless ; wliite 

 oak is inferior to several other oaks and to southern 

 pine, the average breaking-weight of 40 specimens 

 being 386 kilos, while the average of 8 specimens of 

 the southern low oak was 528 kilos; 27 specimens of 

 southern pine gave 490 kilos; 36 specimens of the 

 Douglas fir from the Pacific coast, 374 kilos ; 6 speci- 

 mens of western larch, 523 kilos; 13 specimens of 

 white pine, 274 kilos; 11 specimens of beech, 454 

 kilos; 1(5 specimens of large nut shell-bark hickory, 

 464 kilos; 20 specimens of white hickory, 512 kilos; 

 24 specimens of white ash, 378 kilos; 8 specimens of 

 locust, 543 kilos. 



The next series of tests were made on specimens 

 of the same-sized square as before, and 32 centimetres 

 long, compressing tlaem in the direction of their fibres. 

 Nine specimens of locust stood an average weight of 

 11,206 kilos; 5 specimens of western larch, 10,660 

 kilos; 35 specimens of white oak, 8,183 kilos; 24 

 specimens of southern pine, 10,498 kilos. The effect 

 of tlie pressure on the specimens was very curious. 

 Professor Sharpies exhibited a number of specimens 

 thus treated, which showed curious changes under 

 the pressure. 



The tliird series of tests was to find tlie force neces- 

 sary to indent the wood at right angles to the grain. 

 These are not yet finished, and I can give only a few 

 general results. The load was noted at every one- 

 hundredth of an inch of indentation, and it was found 

 that the first one-hundredth was the hardest to make. 

 After that the amount of force necessary diminished 

 with each one-hundredth, until, at one-tenth of an 

 inch indentation, it was found that the force required 

 was only twice that at one one-hundredth. The 

 specimens were often destroyed, however, before 

 reaching the greater depth. In closing this paper, I 

 wish to express my public thanks to Col. Laidley for 



many valuable suggestions made during the work, 

 and to Mr. Howard for his careful aid in bringing 

 the tests to a successful issue. 



The eozoic and loTwer paleozoic in South 

 Wales, and their comparison Tvith their Ap- 

 palachian analogues. 



BY DR. PERSIFOB FBAZBR OF PHILADELPHIA. 



This paper embodied the observations of the author 

 at St. David's, South Wales, during a visit at the 

 invitation of Prof. Archibald Geikle, director-general 

 of the geological surveys of Great Britain and Ire- 

 land, and Mr. B. N. Peach, geologist in charge of the 

 survey of Scotland. The occasion offered a rare op- 

 portunity for studying those classic rocks, — the Cam- 

 brian ; but thei-e were other series of rocks exposed 

 of the greatest Interest to the student of Appalachian 

 geology, not only from their points of resemblance 

 to other rocks met with frequently on the Atlantic 

 border of the United States, but from the similar 

 relations which they seemed to bear to the measures 

 in contact with them. At Roch's Castle is an area of 

 Llandello flags, resembling what Dr. Frazer has often 

 designated as argillaceous shale; and, In specimens 

 where the decomposition into clay had proceeded very 

 far, there was almost invariably the same disposition 

 .to split into prisms of unequally large pairs of paral- 

 lel planes, no two of which were perpendicular to 

 each other, giving them a remote resemblance to 

 some of the indefinitely numerous varieties of tri- 

 clinic crystals. Like similar argillaceous shales and 

 slates near the town of York, Penn., and elsewhere 

 in America, the slabs split up into almost any desired 

 degree of thinness. The rock on which the castle is 

 built is a sllicious, greenish rock, showing every- 

 where included crystals of more or less definite out- 

 line, and generally of about the size of a buckshot, 

 and containing a whitish or yellowish feldspar. The 

 analogy between this rock and the 'jaspers' of Ro- 

 gers, of which Dr. T. Slerry Hunt was the first to 

 point out the real character. Is striking. In the por- 

 phyry of Roch's Castle, the feldspar is oftener yellow- 

 ish-green tlian in the orthofelsite porphyries of the 

 South Mountain and of the eastern United States, 

 as there is much of the Welsh orthofelsite which 

 shows flesh-colored feldspar, and much of that of the 

 South Mountain which exhibits green and other col- 

 ors. The lamination and flaggy structure, when it 

 was apparent, seemed to be entirely due to the ar- 

 rangement of the cleavage surfaces of numbers of 

 small crystals in the same plane; because a large part 

 of the rocks defied all attempts to define sedimentary 

 structure. Simlllar exhlbilions of orthofelsite are 

 found in quantity on the eastern slope of the South 

 Mountain In Pennsylvania, from Dilsburg to Mon- 

 terey. In the latter regions, however, the beds, 

 which are generally in contact with them, have a 

 more chlorlllc and a more schistose character than 

 the Llandello flags. They are marked, too, in Ameri- 

 ca, for a part of their extent, by an horizon of cop- 

 per ores, of which no trace was observed in South 

 Wales. To the west and north of the beds of intru- 

 sive rock which seem to underlie St. David's, and in 

 the harbor of Porth Cerl, there occurs a thick series 

 of greenish, arenaceous beds, showing numerous 

 streaks of chlorite. They are of very great interest, 

 because they are unmistakably hydro-mica schists of 

 light greelli^h or grayish color, very finely laminated, 

 and resembling the rocks of parts of the South Valley 

 'I'lll, and of parts of Fiillon and Manor townships on 

 the Susquehanna river. Similar schists, which (ac- 

 cording to the writer's theory of structure, based on 



