RANDOM NOTES ON NATURAL HISTORY. 



JET. 



The mineral itself is nothing more or less 

 than a species of pitch coal, found in de- 

 tached masses, grained like wood, splitting 

 horizontal!}', light, and moderately hard. 

 It is often confounded with "cannel" coal, 

 but it is quite distinct. Cannel coal is much 

 harder than jet, has no grain, and splits in 

 any direction. Jet is not easily fused, and 

 requires a moderately strong heat, burning 

 with a fine, greenish-white flame, and emit- 

 ting a bituminous smell. The particular 

 value of jet is, of course, its susceptibilit}' 

 for taking on fine polish. Jet abounds more 

 or less all over the world. In England it is 

 found in greatest quantities in the neighbor- 

 hood of Whitby, in Yorkshire. There it is 

 mixed with bituminized wood, and conifer- 

 ous trees in the upper lias or alum shale of 

 the district. In Prussia it occurs in associ- 

 ation with amber, and is named by the am- 

 ber-diggers "black amber," a phrase which 

 seems to have traveled to Italy, for the 

 mineral is there sometimes called "amber 

 nera." This term is more applicable from 

 the fact, that jet, like amber, becomes elec- 

 trical by friction. There is a belief that 

 amber and jet come from one source ; that 

 amber is a fossil gum, while jet is the trunks 

 and branches of the trees more completely 

 bituminized, and freer from earthy impuri- 

 ties than cannel or other coal. Indeed, M. 

 Magellan goes so far as to say that jet is a 

 pure amber, differing only in color from the 

 undisputed variety. In France large quan- 

 tities are found in the department of the 

 Aude, where a large number of artisans find 

 steady employment in fashioning it into 

 rosaries, religious beads, and ornamental 

 trinkets, when fashion demands them. 



In Spain jet of a very high quality is 

 found at Villaviciosa, in the province of 

 Asturias, and is manufactured principally 

 at Oviedo. But during the present century 

 jet became a popular ornament, and now, 

 probably in not a few minds, Whitby and 

 jet are inseparably associated. The article 

 acquired considerable value, and some 

 twenty years ago jet ear-rings ranged in 

 value from 5s. to 30s. a pair. Then a lu- 

 crative trade was carried on at Whitby, jet 

 miners scooped out pits in the pretty Cleve- 

 land Hills, and a large number of men and 

 young Avomen in Whitby found employment 

 in carving the precious coal into articles of 



feminine ornament. But the success of the 

 English jet trade brought competition into 

 the field, and with it imitation, which latter 

 first demolished the genuine jet trade, and 

 then committed suicide. — Popular Science 

 Monthly. 



Historical Trees of Rhode Island. 



Continued. 



Some of the most remarkable elm trees 

 in the city of Providence are the following : 

 In the northern and oldest part of the city 

 are three grand elms, triangularly situated, 

 one at the junction of North Main Street 

 and Branch Avenue, 12 feet 11 inches in 

 circumference ; its exact age is not known. 

 The great gale of September 23, 1815, blew 

 off one of the prominent branches and split 

 the trunk, which subsequently was secured 

 by an iron bolt, which now lies entirely im- 

 bedded in the tree. The second elm, 13 

 feet 6 inches in circumference, is near the 

 Dickey House, on Branch Avenue. The 

 third one, 12 feet 9 inches in circumference, 

 is located in Abbott's lane, on the site of 

 the oldest house in the municipality. These 

 last two are estimated to be 150 years old, 

 and it has been noticed of late years, that 

 these trees annually increase one inch. 



On the eastern hillside of the city of Provi- 

 dence in Congdon Street, at the entrance of 

 Prospect Terrace, and near the spot where 

 Roger Williams is credited a burial, is a 

 very ancient elm, well preserved, with large 

 spreading branches. The late venerable 

 William Wilkinson thirty years ago said 

 that when he was a boy this tree was then 

 aged. It is safe to say its age is more 

 than two hundred years. 



In the city, at Elm grove, an elm tree 

 south of the pond girths, at four feet from 

 the ground, 14 feet 5 inches ; another, west 

 of the pond, 12 feet 5 inches. On Admiral 

 Street, in front of the old residence of Com- 

 modore Esek Hopkins, is a fine spreading 

 elm of 11 feet girth, planted by his daugh- 

 ter in 1786. In Pawtucket an elm on Main 

 Street, measuring 17 feet in circumference, 

 has recently been removed. Over the city 

 limits on Plainfield Street, in Johnston, are 

 three elms, girth five feet from the ground, 

 about sixteen feet. These trees were prob- 

 ably set out in 1748. J. H. B. 



Providence Journal. 



(To be continued.) 



I 



