G I A N T 



alfo at Dunliice-hill, neaf ttie eaftle of Dunluce ; in the bed 

 of the river Bulb, near the bridge of Bufh-mills ; on the 

 fiimmit of the mountain of Croaghmore ; in many parts of 

 the high land over Ballintoy ; in the iiiand of Raghery, op- 

 pofite Bailycaftle, and various other places, through an 

 extent of coaft about fifteen miles in length and two in 

 breadth. Beyond this trad, which abounds in perfect pil- 

 lars, an attentive obferver will be able to trace the fame 

 materials and ftratification in very dillant parts of the coun- 

 try, as far as the northern fhore of Loughiieagh, and the 

 mountanis of the county of Derry ; in many places of which 

 imperfect columnar forms may be obferved ; fo that the 

 great caufe which generated this fpecies of lloi* has been 

 exerted through a fpace of more than forty miles in lencrth 

 and twenty in breadth ; that is, through above eight hun- 

 dred iqua;e miles. 



Of the different varieties obfervable in the column* that 

 compofe the Giants Caufeway and thofe of the other parts 

 of the coaft, the following comparative view has been given 

 by Mr. Hamikon. i . With refpeft to form and magni- 

 tude : the pillars of the caufeway an- comparatively fmall, 

 not very much exceeding one foot in breadth and thirty in 

 length ; fliarply defined, neat in their articulation, with 

 coavex or concave terminations to each joint. In many of 

 the c-apes and hills they are of larger ilze, more imperfect 

 and irregular in tlieir figure and articulations, having often 

 fiat terminations to their joints. At Pairhead they are of a 

 gigaiitlc magnitude, fometimes exceeding five feet in 

 breadth and a hundred in length ; often apparently deftitute 

 of joints altogether. 2. With refpeft to fituation : the 

 pillars of the Giants Caufeway iland on the level of the 

 beach, from whence they may be traced, through all degrees 

 of elevation, to the lummit of the higheft grounds in the 

 neighbourhood, as at the old fort of Dunmull, and on tke 

 top of Croaghmore, fix hundred feet at lealt above the level 

 of the fea. 3. With refpect to dilpofition and arrange- 

 ment : at the caufeway, and in moll other places, they 

 Hand perpendicular to the horizon ; in fome of the capes, 

 and particularly near Uihet harbour in the ide of Ragheiy, 

 they lie in an oblique pofition ; at r>oun-point, in the fame 

 ifland, and along the Ballintoy (hore, they form a variety of 

 regular curves. 4. With regand to colour and grain : 

 the Giants Caufeway bafalt is blackifh, dole, and uni- 

 form ; its varieties of colour are blue, reddifli, grey ; and 

 of grain, all that can be fuppofcd from extreme finenefs to 

 the «oarfe granulated appearance of a ilone, which refembles 

 imperfeft granite abounding in cryilals of fhorl, chigfly 

 black, though fometimes of various colours. 5. With rc- 

 fpcd; to texture : though the Giants Caufeway bafalt be 

 in general compaft and homogeneous, yet the upper joint 

 of each pillar, where it can with cei-tainty be alcertained, 

 is always rudely formed and cellular. The grofs pillars alfo, 

 in the capes and mountains frequentty abound in thefe air- 

 holes through all their parts, which fo-mctimes contain iiiie 

 clay and other apparently foreign bodies : and the irregular 

 bafalt beginning where the pillars ceafc, or lying over 

 them, is, in general, extremely honey-combed, containing 

 in il s cells cryitals of zeolite, little morfels of fine brown 

 clay, fometimes very pure lleatite, arid in a few inltances 

 bits of agate. 



The inland pillars, upon the whole, differ from thole 

 whicli run into the fea, and are called the caufeway, oiJy in 

 the following particulars ; fome of the inland pilars are 

 much larger than thofe of the caufeway, being two feet 

 and a half in diameter, and am.ong thefe there are only 

 found fuch as have three, four, five, and fix fides, none of 

 ihem having yet been found lo have feven or eight tides, as 



many of thofe of the «ufeway itWi liave. An J, /IraDv 

 theie mlard pillars, though compofed <;f as many joii.l's 

 as thofe of the caufeway, yet have not that turioiis" arti. 

 culation of the ball and focket, but are only joined bv 

 the laying one fmooth furface on anotlu.r ; fo tliat a joint 

 of a lingle colunni may be l!ij;ped off from the rel», by 

 a conhderablc force prcffing againft it. There is fumi- 

 tliing like this obfervable alfo ii, fome of the columns of 

 the caufeway itfelf; for among llit- nnii.bers which are 

 jointed by the bail and focket, there are fome which only 

 ad here by being applied furface to furface. This is found 

 only m a few of the colum.u, however, and they always 

 Iland within the chifters, and are con-.pofed of 'lefs thau 

 feven fides. In thefe alfo the joint is not made by tl c 

 apphcatwn of two hori/onul planes, but by fuch as flant, 

 fo that It looks very hke the breaking of 'an cntrochus or 

 aileria. 



The joints, as we fee the pillars above the furface, arc 

 ufually as many in number as the pillar is feet high; but 

 they are net regularly each of a foot long, for they arc 

 jhortell at the upper part of the columns, and run gradually 

 longer and longer as they approach the bafe. This is ob- 

 ferved both in the inland columns, and in thofe of the caufe- 

 way ; but though tbe length of the joints differs, their 

 convexities and hollows are niuch the fame in all parts of tlie 

 column. 



Ti:ere are other bafaltic columns, fimilar to thofe above 

 defcribed, in our own ifland ; particularly at Staffa, one of 

 the weflern illands of Scotland ; in the mountain of Caderi- 

 dris, near Dolgelly, in Mcrionethlhire ; whcie they proba- 

 bly form a group as in other places. Mr Strange has o-iven 

 an account of two groups of prifmatic bafiJtinc columns, 

 which he difcovered in the Venetian flate in Italy ; one ia 

 Monte Roffo, about feven miles nearly fouth from Paiiua, 

 and the other in Monte del Diavolo, near San Giovanni 

 Illarime, about ten miles north-weft of Vicenza. The form 

 of the latter is nearly circular, refetnbhng that of the Giants' 

 Caufev.ay ; that of the former approaching more to an ob- 

 long or oval figure : the columns of San Giovanni are much 

 about the fame fize, and mcafure about a foot in diameter ; 

 thofe of Monte Roflb are very unequal, fome being a fool, 

 while others fcarcely exceed three inches in diameter : thofe 

 of both thefe Venetian groups manifefl all the varieties of 

 prifinatic forms obfervable in the Giants' Caufeway, and 

 other fuch groups ; but they are commonly of live, fix, or 

 fcveii fides, and the hexagonal form fecn-.s moftly to prevail. 

 The texture of the former fort is folid and miiform ; the fur- 

 face fmcotlu and the internal parts of a dark iron-grey 

 colour ; thofe of Monte RolTo have a rough and kiio'lr 

 furface; and, when broken, manifella v^'riegated colour, 

 and unequal texture of parts ; refembhng an inferior fort of 

 granite, of which the mounttJn is formed, and which ferr.n 

 as a bafe for this range of columns. Oilier groups of arti- 

 culated bafaltine columns liave alfo been cbfcrved in the pro- 

 vince of Velay and Auvergne in France ; particularly by 

 M. De Varennes, at Blaud near Langeac, aud by M. D.;'- 

 marets, near le Mont d'Or ; and M. Sage mer.tions another 

 near St Alcon, in the fame province. Kircher has long 

 ago defcribed a group of the fame columns near Viterbo iii 

 Italy. Mundus Snbterran. lib. viii. $ i. cap. 9, S:c. And 

 Mr. Strange mentions another at Caflel Nuovo, in the Eugn- 

 nean hills, about four miles fouth-well of that of Monte 

 RofTo. . . 



For the various controvcrfies with regard lo the origin of 

 thefe bafaltic columns, and of the fletz-trap-rocks iu general, 

 fee Tkap. 



GlASTs' lltad, in Gcorrtifly, r. c.tnc «n tl:e e^ft coaJl 

 "G g 3 ' ' of 



