342 



BGIENGE. 



[Vol. VIII., No. 193 



provision of the agreement has been violated, and 

 the result is a pavement such as shown in trans- 

 verse section in fig. 2. The road-bed, or sub- 

 grade of earth, vs^as not excavated to the proper 

 depth, leaving the surface of the pavement at the 

 centre of the street three inches higher than the 

 established grade, making a steepness of crown or 

 arch between curbs detrimental to traffic as com- 

 pared with a flatter surface, and actually dangerous 

 in icy weather. The surface of the road-bed was 

 not tamped ; the concrete ranges in thickness 

 from the stipulated six inches down to three, 

 and in some places even two inches ; it was not 

 properly mixed, laid, or tamped ; and the mate- 

 rials of which it is composed are inferior in quality. 

 The granite blocks vary gxeatly in size, and are 

 bedded in a mixture of sand and gravel. They 

 are laid with the broadest edge upward, instead 

 of the reverse ; the filling between them is a mix- 

 ture of sand and gravel ; and the paving cement, 

 instead of filling the interstices to the bottom of 

 the block, extends only an inch or two below the 

 surface. In fact, so imperfect are both material 

 and workmanship, that, after a short period of 

 heavy traffic, the pavement will present the ap- 

 pearance shown in fig. 3. All sand and gravel 

 used should have been free from moisture, artifi- 

 cially dried if necessary, and the joints between 

 the blocks should be water-tight. These conditions 

 were violated, and the collection of water at W in 

 fig. 4 shows the effect of damp bedding and leak- 

 ing joints. As a result, the tremendous pressure 

 due to the expansive force of the freezing of this 

 water in cold weather may be expected to rupture 

 the pavement at the point where the water collects. 



8T. PETERSBURG LETTER. 



Russian science has sustained a heavy loss by 

 the death of A. M. Butlerow, the celebrated 

 chemist, in August last : it is the greater, as he 

 was yet in the prime of life. His chemical work is 

 well known abroad, but it may not be known that 

 he had a second specialty : he was an eminent 

 apiculturist. The progress in bee-keepmg made 

 in the last years in Russia owes much to his un- 

 tiring efforts, especially to his manuals and papers. 

 By his death the second chemical seat is made 

 vacant in the Academy of sciences ; and various 

 surmises are made as to whether this learned cor- 

 poration will persist in its opposition to the elec- 

 tion of the greatest of Russian chemists. Professor 

 Mindeleff. 



Professor Mindeleff has twice visited the petro- 

 leum district near Baku, on a mission of the 

 Muiistry of finance, principally with a view to as- 

 certaining if the wells were rapidly giving out or 



not. He has not yet returned from his last 

 joui'ney. Great progress is said to have been 

 made in the distillation of petroleum oils by G. 

 W. Alexeyew. 



It being now early in the season, news about 

 geographical expeditions is yet scarce. Prjevalsky 

 is still at his country-seat, working at the report 

 of his last journey, which is to be ready in 

 August next. The special reports on botany, 

 different parts of zoology, and probably also geol- 

 ogy, it will take a long time to complete. The 

 only special report which is to appear sooner is 

 that on meteorology. The observations during the 

 last expedition will be printed in extenso, together 

 with those made during the Lob-Nor and the 

 second Tibet expeditions of the same traveller, 

 and the itineraries of the same. The work is to 

 be supervised by Prof. A. Woeikof, who will add 

 to it a work, on the climate of the countries trav- 

 ersed, and High Asia in general. 



The Russian polar commission has printed the 

 observations of the first year (1882-83) of the 

 Lena expeditions, which comprise meteorology 

 only. The work of the second year, as well as 

 the calculation of the magnetical observations, is 

 in preparation. The work of the Lena expedition 

 is of the highest character, and does the greater 

 honor to its members, as it was done under the 

 most serious difficulties. 



Great progress in meteorological work in the 

 south of Russia has been made. Professor 

 KHossowsky, in Odessa, has succeeded in establish- 

 ing quite a number of rainfall and thunder-storm 

 stations in the government of Kherson, one of 

 the most extensive in the south, and will issue a 

 monthly report. This year was remarkable for 

 heavy rains, especially in the southei'n part of the 

 government. The rains have also extended to the 

 central and eastern parts of Russia, and seldom 

 have so heavy rainfalls been experienced on one 

 day in this country. Till this year, over one hun- 

 dred millimeti'es fell on one day at but two places 

 in the ]Dlains of European Russia, — 145 in the 

 southern part of the government of Tula, July 

 12, 1882; and over 120 at Yelisavetgrad. This 

 summer we had 132 at Kharkow, June 24 ; 102 at 

 Lgow (government of Koorsk), July 30-31 (of 

 these, 51 in one hour) ; 99 at Moscow, Aug. 9-10 ; 

 93 at Kamishin, July 28. The rain of Aug. 9-10 

 was very heavy over a great district, and caused 

 high water in the right tributaries of the Moskwa 

 and Oka. The railroad-bridge over the Lopassnja 

 was washed away. 



Captain Makarow, I.R.N. , has published an im- 

 portant work, "On the interchange of waters 

 of the Black and Mediterranean seas." By the 

 use of an instrument called a ' fluctometer,' 



