DORSETSHIRE. 



. isle of Purbeck ; and in a quarry to the north-west of 

 T~ """ " tin 1 isle lit' Portland. Hut the most singular substance, 

 *^&' in a geologii il |M>int of view, is the Kimmcridge coal, 

 which is found in a small and very |>oor village of that 

 name, in the Nle of Purln-ck, where the cliffs arc cut 

 down rather abruptly. The cliffs are composed of slate 

 clay, with animal and vegetable impressions. The out- 

 side ul'tlie rock is covered with a thin layer of calcare- 

 ous sp-ir. The first transition is to the slate clay ; the 

 second to a bituminous slate, called tlony coat, the spe- 

 cific gravity of which is l.'U}). It has no lustre, is of 

 a dark brown colour ; effervesces slightly with acids ; 

 hums readily with a yellowish heavy flame, gives out 

 a bituminous, rather than a sulphureous smell. When 

 exposed to the atmosphere, it falls to pieces ; but when 

 kept under water, or before it is dry out of the cliffs, 

 it is very hard. It is u<e<l as fuel by the poor people in 

 the neighbourhood, and the ashes are considered as af- 

 fording good manure for meadow land. There is no 

 coal in this county, nor any mines of metals. It is, 

 however, compensated for these deficiencies, by the 

 stone quarries of Portland and Purbeck, and by the 

 potters' clay of the latter. Some geological notices have 

 already been given of the quarries ; but these, as well 

 as the pits of potters' clay, deserve particular notice. 

 Portland The isle of Portland, which is four miles and a half 



tone quar- in length, and two in breadth, has long l>een famous 

 for it> stone quarries, and indeed may be said to be one 

 continued bed of stone. It is free-stone, and peculiar- 

 ly deserves this appellation, from the facility with which 

 it can be cut in any direction, whether horizontal, per- 

 pendicular, or parallel to the site of the strata ; and it 

 bears the weather equally well in every position. In 

 the quarries, the first stratum is one foot of blackish or 

 reddish earth ; then six feet of cap or stone, which is 

 not fit for exportation ; below the cap, the good stone 

 runs for ten or twelve feet deep ; and below this is flint 

 or clay. The stratum of marketable stone lies nearly pa- 

 rallel with the upper surface of the island. There are 

 several beds of stone lying one upon another, from two 

 to four feet in tlu'ckness. The cap is first removed ; af- 

 terwards, the quarrymen cross-cut the large flats, lay- 

 ing bare, with -wedges. By means of those, and the 

 blows of a tool called a rivet, blocks are formed, with- 

 out much difficulty or labour, from half a ton to six or 

 eight tons weight. These blocks are conveyed to the 

 shore by a simple contrivance. There are low cars, 

 with solid wheels, which sometimes carry six tons; 

 when going down- the steep hill, which lies between 

 the quarries and the pier, they tie behind them a sledge, 

 loaded with a large stone, which prevents the car from 

 pressing forward on the horse. The expence of digging 

 and squaring is lls. per ton ; the owner of the land 

 has I s. 6d ; and it costs 6s. a ton more before it is ex- 

 ported. About 14s. a ton in time of war, and 10s. in 

 time of peace, is paid for its freight to London. It is 

 calculated that, on an average, 100 blocks will weigh 

 80 tons. The inhabitants in the isle of Portland are 

 stated to be 1 700, of which 800 are employed as quar- 

 rymen. The ships engaged in the trade are 50, from 

 30 to 140 tons burden. The stone exported annually 

 is from 20 to 30,000 tons. The horses employed in the 

 trade are 180 ; six of them are usually put in one team, 

 price of the stone is from l6s. to 24s. the ton, of 

 16 cubic feet. The duty on the stone, when delivered, 

 is about 6s. per ton. Portland stone is said to hav e I en 

 first brought into use and reputation by James I. who 

 emplovedit in the erection uf the Banqueting House at 

 Whitehall After the fire of London, it was much used 



by Sir Christopher Wren, in constructing the different Dorsckhfaa. 

 publii '*^~, ""- 



The isle of Purbeck has also several valuable stone Purbeck 

 ({lurries, the principal of which arc in the neighbour- "ine qur- 

 hood of Swana.se. The stone differ* from that of Port- *** 

 land, and is not so valuable or useful. It is principal- 

 ly composed of shells and other marine remains, ce- 

 mented very closely by calcareous spar. That which 

 is got at Swanasc takes a fine polish, and looks like ala- 

 baster ; formerly a kind of black stone, called Purbeck 

 marble, was obtained. Sonic fine specimens of it are to be 

 seen in the church at Christ-church. The pillars of Salis- 

 bury cathedral are also made of one species of Purbeck 

 marble. The hills, out of which the stones are dug, run 

 nearly east and west. Near the shore, they are ^00 or 

 500 feet high, and higher inland. The dip is very consi- 

 derable to the north, the uppermost bed of stone lying 

 near the surface, while, in about 300 yards, it sinks be- 

 low the sea. The average export of this stone is about 

 40,000 tons. It is mostly used for flag-stones for pa- 

 ving ; and the greatest part is shipped from Swanase 

 for London. The price is about 40s. per hundred feet 

 superficial. The thickness is generally from 2^ to S 

 inches ; and reckoning that 1 4 cubic feet are a ton 

 weight, a hundred superficial feet will weigh about If 

 tons. The men employed in digging the stones are about 

 300. The ground rent paid to the owners of the land 

 is about 6d. per ton for all kind of stones raised here. 



Potters' clay is found in great abundance, and of ex- Potter** 

 cellent quality, in the northern division of the isle of clay. 

 Purbeck ; and it probably forms the substratum of the 

 whole tract, which may be called the Trough of Poole. 

 The existence of alumine, lime, magnesia, oxide of iron, 

 and silica, has been detected in some specimens of it ; 

 but, in general, it is very free from these substances. 

 It feels greasy and smooth, and varies in colour from 

 ash grey to blue. It contains sometimes cylindrical 

 blue nodules, (to which the workmen give the appel- 

 lation of pint,) the texture of which is close, and the 

 composition probably more ferruginous. The specific 

 gravity of the purest specimens is about 1.723. The 

 principal pits are to the west of the road between Ware- 

 ham and Corfe Castle, where the stratum extends about 

 three miles in length, and one in breadth : the depth, 

 as well as the quality, varies very much. Farther to 

 the east is a kind of clay of a brown colour, which 

 .shrinks very much in the fire. It is reckoned that about 

 20,000 tons are annually exported, principally for the 

 use of the potteries in Staffordshire. The inferior kinds 

 are sent to London and Bristol, to make brown stone- 

 ware. The goodness of the quality depends chiefly on 

 the small proportion of iron which it contains ; where 

 there is much of it, the clay will not burn white, and 

 the particles of iron cause it to blister. Upwards of 

 100 men are employed in the clay pits ; many more 

 were employed before an iron rail-way was constructed, 

 from near Corfe Castle to a small harbour opposite 

 Poole; to which it is carried in boats, and snipped 

 thence for Liverpool, London, &c. As the digging of the 

 clay requires great care and attention, it is seldom done 

 by piece-work, but commonly by the day. Three shil- 

 lings and sixpence is the usual wages. It is delivered 

 in Poole harbour at 20s. a ton, and Sicwt. extra is allow- 

 ed, on account of the loss of weight which it experi 

 ences. A species of chalk, found near Rampi&ham, 

 deserves notice : it seems a kind of Tarras, as it has the 

 quality of growing (as it is termed) under water, i. c* 

 it swells, and at tlie same time becomes harder. 



Dorsetshire is not u manufacturing county. In the 



