516 
Prof. Milne — Across Europe and Asia. 
tlian an kour we kad crossed tke flying bridge, and were safely at the 
end of tkis section of my joumey : tbe distance from Tomsk being 
about 1559 versts, or 1036 Englisk miles. Irkutsk is a large town. 
of about 30,000 inkabitants, containing many fairly kandsome build- 
ings. It is situated on tke N.E. side of tke Angara, opposite to its 
junction witk the Eiver Irkut. Like St. Petersburg, it may be said 
to have been built upon a tnarsk. In 1652 there were only two 
kouses upon tke present site, but soon after, in 1686, by order of tke 
Government, tke town as it now appears began to rise. Altkougk 
tke town itself is flat, tke surrounding country is undulating. All 
along tke sides of tke rivers, and running for some distance up tke 
slopes of tke kills, tkere are beds of alluvium. On the kills tkem- 
selves tkere is a covering of yellowisk eartk from two to tkree feet 
in tkickness, wkick, from the fragmentary stones it contains, can be 
seen to kave been derived from tke disintegration of tke subjacent 
rocks. These are in tke rnain a grey and yellowisk sandstone, 
slightly micaceou8, and somewhat gritty. Tkis is quarried and used 
as a building stone in tke few places wkere stone is required about 
tke town. In some places it is conglomeratic. Whilst examining tkis 
rock upon tke nortli-east side of tke town, I found several tkin vein- 
like seams of coal. These veins, wkick kad a brownish lignitic 
character, were from two to four inckes in tkickness. In tke sur- 
rounding districts many outcrops of tkis material kave been found, 
wkick unfortunately appears to lack rnore in quality tkan it does in 
quantity. Erom fossils wkick kave been found in this formation, its 
age, as I kave before stated, wken speaking of tke coal-fields of tke 
Erals, is probably Jurassic. About 40 miles to the north- west tkis 
overlies a limestone, wkick is probably of Devonian age, but even 
about tkis tkere is some doubt. Besides tke strata on tkese two 
horizons, tke only otker rocks in tke district appear to be eitker 
kighly metamorphic or eise volcanic in tkeir origin. The former of 
tkese rocks are well developed along tke valley of tke Eiver Tunka. 
The rugged mountains wkich bound tkis valley, called tke Tunkusian 
Alps, can be seen from Irkutsk. Mr. Tchersky, wko kas explained 
tkis district, kas described a remarkable series of graduations as 
occurring tkere. Tke series commences with limestone, passes 
tkrough pyroxenic rocks, and ends witk rocks tkat are granitic. 
Up tkis same valley perched boulders of a local origin kave keen 
found. Tkeir discoverer, Mr. Tchersky, attributes tkeir origin to 
glacial action, but on tkis point local geologists are not agreed. The 
only otker plienomena wkick can be assigned to tke action of ice are 
tke scratcked stones in the alluvium of tke river-banks, but tkese 
are only such as are produced every year. So, as I kave before said, 
we kave not yet any uudoubted evidence of polar ice-caps or large 
glaciers. 
Besides coal, whick I have spoken of, Iron ore, Gypsum, and 
Kaolin are found in the neigkbourkood. A small quantity of gold 
is also worked, and once there was a lead-mine. Tke best returns 
appear to be derived from tke salt springs, as at Tailma, wkich was 
a Station I p issed tkrough before reacking Irkutsk. 
