July 31, 1891.] 



SCIENCE. 



61 



PapaveracecB are represented especially by dwarf, large- flowered 

 kinds of ileconopsis. Tbe greater number of the species of Cory- 

 dalia are not more than two or three inches high. The Oruciferce, 

 such as Parrya ciliaris, in the same way are dwarf and large- 

 flowered. Silene ccespitosa may be compared with the most dwarf 

 states of S. acaulis of our own high mountains. The honeysuckle 

 of Thibet constitutes only a small bush about a foot high, with in- 

 tertangled branches. But it is especially in the rhododendrons 

 and primulas that this dwarf character is remarkable. All the 

 rhododendrons and primulas found between Lhassa and Sitang — 

 -B. prineipis, R. primulceflorum, R. nigropunetatum, Primula 

 lepiopoda, P. diantha, and P. Henrici — may be ranged amongst 

 the dwaifest types of the genera to which they belong. It is the 

 same with Incarvillea. The Thibetan species belong to a group 

 found also in Kansu and central Yunnan, with stem almost ob- 

 literated and corolla very large. Passing eastward in Szechwan 

 the flora puts on a difi'erent character. The leaves become larger, 

 the number of flowers to each plant increases. There are many 

 RosacecB, orchids, and species of pedicularis ; amongst the Com- 

 positce the genus senecio is particularly well represented, and there 

 are several everlastings that approach the edelweiss of the Swiss 

 Alps. The flora of this eastern part of Thibet and western region 

 of Szechwan has a strong affinity both with that of the Sikkim 

 Himalaya and that of central Yunnan. Meeonopsis Henrici repre- 

 sents the Himalayan M. simpUcifolia Hook, et Thoms. ; Astragalus 

 litargensis, A. acauils Benth. , Rubus xanthocarpus, R. sikkimen- 

 sis ; Brachyactis chinensis, B. menthodora ; Onaphalium eorym- 

 bosum answers to G. nubigenurn ; Androsace bisulca to A. micro- 

 phylla; and there are many other similar parallels between the 

 plants of Thibet and Sikkim, and in the same many parallels may 

 be found between the new species found by the travellers in Thibet 

 and those gathered by Delavay in Yunnan. 



— The numerous letters received at the Wisconsin Agricultural 

 Experiment Station in relation to the chinch bug show that this 

 pest has already done much harm to wheat and barley in some 

 sections of that State, and that it is now moving from the grain 

 fields into the corn fields. Any remedies tried must be quickly 

 applied. It is now too late to introduce infected bugs, such as 

 have been sent out by Professor Snow of Kansas. The kerosene 

 emulsion remedy which is now being successfully used by Dr. E. 

 Fred Russell of Poynette, Columbia County, is recommended. It is 

 made as foUows: Slice half a pound of common bar soap; put it 

 in a kettle with one gallon of soft water and boil until dissolved ; 

 put two gallons of kerosene in a churn or stone jar, and to it add 

 the boiling hot soap solution; churn from twenty to thirty min- 

 utes, when the whole will appear creamy. If properly made no 

 oil will separate out when a few drops of the emulsion are placed 

 on a piece of glass. To each gallon of the emulsion add eight 

 gallons of water and stir. Apply with a sprinkling pot. Every 

 farmer should learn to make this emulsion as it a most useful in- 

 secticide. It is especially valuable for killing lice on cattle and 

 hogs. Paris green will not kill chinch bugs. If the bugs are not 

 yet in the corn, plow a deep furrow along the side of the field 

 they will enter and throw into it stalks of green corn. When the 

 bugs have accumulated on the corn, sprinkle with the emulsion. 

 Put in fresh stalks, and sprinkle whenever the bugs accumulate. 

 If they break over the barrier, as they probably will, run a new 

 furrow a few rows back in the com and repeat. Where they have 

 attacked stalks of standing corn, destroy by sprinkling. If the 

 remedy is tried it should be used persistently. To kill one lot of 

 bugs and then stop will do little or no good. When the bugs 

 threaten to destroy as much as five or ten acres it will pay for one 

 or two men to devote their whole time to the warfare. Only a 

 jtart of each day, however, will be needed. Some com will be 

 lost at best, but the most of the field should be saved. Any one 

 trying the remedy is requested to send the results of his experience 

 to the experiment station. 



— Professor Martens of Berlin has published in the Mittheil- 

 ungen aus den Kceyiiglichen technischen Versuchanstalten zu Berlin 

 a report (summarized in Engineering of July 17) of some experi- 

 ments on the strength of steel at various temperatures between 

 3®' C. and 600° C. The material used consisted of mild steel. 



having a tensile strength of 33 tons, 27 tons, and 30 tons per 

 square inch. The bars from which the test pieces were cut were 

 1.5 inches in diameter and were thoroughly annealed. A number 

 of bars of the same quality of metal were all tested in the usual 

 way, both after annealing, and as received from the makers, so as 

 to form a standard for the other bars. The temperatiire of the 

 bars was made uniform by placing in a bath and testing them there. 

 For the low temperature tests the bath was filled with a freezing 

 mixture, and for the high temperature tests, with paraffine, up to 

 200° C, beyond which alloys of lead and tin were used. The 

 contents of the bath were warmed by gas jets, and stirred during 

 the course of the experiments. The elongations of the bar up to 

 the yield point were taken on a length of 8. 1 inches by means of 

 a mirror apparatus, the diameter of the tested portion being 0.79 

 of an inch, and autographic diagrams were also taken of each 

 specimen. The results of the experiments showed that the elastic 

 limit of tbe material became lower as the temperature rose, though 

 the falling off was not very serious up to 200° C, but beyond that 

 point it lowers somewhat rapidly, and finally seems to disappear. 

 The maximum stress decreases from 20° C. up to 50° C, but af- 

 terwards rapidly rises to a maximum somewhere between 200" 

 and 250° C. Taking the strength of the specimen at 20° C, 

 Ihe maximum stress for the 23-ton steel is 1.34 greater, and the 

 maximum breaking stress is 1.62. For the 27-ton steel the figures 

 are 1.27 and 1.45, and for the 30 ton steel 1.25 and 1.50. The 

 contraction of area for all the specimens was least at about 

 300" C. 



— London Engineering announces the formation of a British 

 syndicate, to be known as the Great Lakes Navigation Trading 

 Company, Limited, having a capital of one million sterling with 

 which to establish a fleet of ten steamers, each of 1,500 tons, to 

 establish water communication between Chicago and Great Brit- 

 ain via. the Great Lakes. The vessels are to be of such dimensions 

 as will enable them to pass through the locks on the Canadian 

 canals, and it is said that they will be ready for starting the ser- 

 vice next spring. Keeping in mind the restless activity of Chi- 

 cago, says the journal named, it is surprising that no regular ser- 

 vice of steamers has been started between that port and Britain. 

 There is sufficient traffic. In the Great Lakes there was carried 

 in 1889 nearly 27,500,000 tons of cargo, the fleet of steamers con- 

 sisting of 2,055 vessels, of 828,000 tons, worth nearly twelve mil- 

 lions sterling. The arrivals and clearances at Chicago have in ten 

 years increased by 73 per cent to 10,250,000 tons, and it is possible 

 to conceive of an equally large increase in the next decade, for 

 54,411 miles of railway terminate in that city, and in a year work 

 43,000,000 tons of freight. Besides, in the central northern and 

 north-western groups of States the total tonnage of freight moved 

 is 196,000,000 tons. A fair proportion of this comes to Europe, 

 principally grain; and probably if througti sea communication 

 could be established and freight rates reduced, a stiU larger quan- 

 tity might be sent. The distance from Chicago to Liverpool by 

 the lakes and via New York does not differ much. By the lakes, 

 Welland Canal, and St. Lawrence River, 4,488 miles, and via 

 New York by rail, 4,353 miles; so that the latter distance can be 

 covered in 337 hours against 346 hours in the other case. By rail 

 to Montreal and thence by steamer the distance is 4,062 mUes, re- 

 quiring 328 hours. But after all, time is not a material considera- 

 tion in cargo traflic. The freight rates should decide. Mr. Cor- 

 thell, in a paper read recently before the Canadian Society of Civil 

 Engineers, strongly advocates the development of this lake trade 

 to England, by the deepening and lengthening of locks and canals, 

 and the construction of ship railways, and he gives figures based 

 on average rates to show that it is probable that freight could be 

 carried by way of the lakes at half the cost of that sent by rail to 

 New York or Montreal, and thence by steamer to Britain. If this 

 be so, then the Chicago people, and particularly Canadians, will 

 do well to study the matter, because to Canada, possibly more 

 than to America, Britain may in the future have to look for grain 

 supplies. The new syndicate wisely lay themselves out for a dis- 

 tinct trade. The vessels are to have extensive refrigerators. To 

 overcome the disadvantage of the season of ice-bound rivers, which 

 continues for rather more than a third of the year, a terminus is 

 to be made at Portland, Maine. 



