G N O 



GNOIEN, a town of l!ie diicliy of Mccklonliurg ; 21 

 miles E.S.E. of Rottock. N. lat. 53-^ 59'. E. loinr. 12' 

 52'. 



GNOLL Raii.-Way. This is an eRabliflimcnt in Ola- 

 !n>.i-ganlliire, in South Wales, which we had not heard of at 

 the time of coinpiUng our article Canai, ; it is called an 

 iron 'U'ai^go/i-'way, the fl.inch being on the wheels of the 

 wai^t^oas; ;;;!k-iid of being on the tram-plates, as is more 

 ■commuii in that diilritt. It commences at the Ihipping- 

 place 200 y;u-ds below Neath bridge, on the Neath river; 

 jrofies the Neath canal on a wooden bridge, and proceeds 

 about E. half a --mile to the late fir Herbert Mackworth's 

 (rnoll collieries, of run coals, which are drawn up forty 

 r;ith;>m, to be loaded into the waggons on this waggon-wav, 

 svhich has fo regular a defcent, as to require no inclined 

 planes, or other confidenible works. 



GNOMES, Gnomi, a name which the Cabbalills give to 

 certain invillble people, whom they fuppofe to inhabit the 

 ■inner parts of the earth, and to lill it to the centre. 



They are reprcfented as very fmall of llature, traftable, 

 and friendly to men ; and are made the guardians of mines, 

 quarries, hidden treafures, &c. Vigcnere calls them 

 Gnomons : the females of this fpecies are -called Gno- 

 niides. 



Vigneiil de Marville, in his Melange de Hiftoire ct de 

 Literature, tome i. p. 100, gives a relation of a conferenc* 

 with a pliilofopher of this clafs, who held, that an infinity 

 of fpirits inhabited each of the four elements, fire, air, 

 -water, and earth, under the denomination of SalamanJirs, 

 Sylpks, Oudins, and Gnomes ; that the Gnomes are employed 

 in working or aftuating the machines of brutes upon 

 earth. 



He added, that fomo philofophers of that feft held that 

 thefe fpirits were of two fexes, for the two fexes of bealls 

 or moving machines ; that tliey were more or lefs perfect as 

 the brutes were ; and that there was an inlinite number of 

 exceedingly fmall ones, to actuate the infinite number of 

 infefts and animalcula, both thofe that are vifible, and thofe 

 which are too fmall to come under our fenfes ; that all 

 thefe fpirits, in general, govern their refpeitive machines 

 according 10 the difpofition of the parts or organs, the 

 humours, temperaments, &c that they do not la\ hold of 

 all machines indifferently, but of thofe fuited to their own 

 cliafafler, clement, &c. that a haughty one, for inlhnice, 

 feizes a Spanilli gennet ; a cruel one a tyger, &c. 



Gvo.ME, Tvi'^r, or chna, is alio ufed lor a Ihort, pithy, 

 and fententious obfervation, reflection, or tlie like, which 

 is worthy to be treafured up and remembered. 



Such is that of Juvenal, " Orandum ell, ut fit men"; far.a 

 in corpore fano." The writers of rhetoric dillinguifli fevcral 

 kinds of gnomes, according as they turn on words, on 

 aftions, or both ; denom.inating them -verbal, aSive, and 

 i«/.vft.' gnomes or chrtJ. See Apophthegm. 



GNOMON, in Dialliiig, is the llyle, pin, or cock of a 

 dial, the fiiadovv whereof pointcth out the hours. 



The word is Greek, 'yi^u^-, which literally miports foir.e- 

 what that makes a thing known ; becaufe the Ityle or pin 

 indicates or makes the hour, &c. known. 



The gnomon of every dial is fiippofed to rcprefent the 

 axis of the world ; and therefore the two ends or extremi- 

 ties theivilf mull direftly anfwer to the north and fouth poles. 

 See Dial and Dialling. 



Gno.mon, in Geometry. If a parallelogram be divided 

 into four lelfer ones,, by two lines interfeetmg each other, 

 and one of thefe parallelograms be retrenched or taken 

 away, the other three will make a gnomon, orduiarily called 

 a ftjiiare. 



Vol. XVI. 



G N O 



Or, a gnomon, in a parallelogram, may be faid to be a 

 figme formed of the two complements, together with 

 either of the parallelograms about the diameter. Thus, in 

 the parallelogram A C, PlaleVlll. Geometry, f^. 96, the 

 gnomon is M -|- .v + c -f N; or M + N -i- X -r Z. 



Gno.MON', in yljlronomy, the name given to any upright 

 pillar, when ufed for the i)urpofe of determining the alti- 

 tude of a celedial objeft, but particularly the fun. 



The extreme fimplicity of this inilrument renders it very 

 probable, that it was the tirft ever ufed for aflronomical 

 purpofes. It fortunati'ly happened for the fcience, that it 

 was capable likewife of being a very exaft one ; and all the 

 knowledge the ancients had of the folar theory feems to 

 have been derived from this inilrument. The principle of 

 it is fo iimple, as hardly to require explanation. If the height 

 of a vertical pillar be compared with its (liadow on a hori- 

 zontal plane, the altitude of the fun may be deduced by 

 trigonometrical calculation, fince thefe two quantities are to 

 each other, as the tangent to the radius, or as the fine to the 

 cofiiie of the altitude required. The ancient obelifks found in 

 Egypt and the Eall were probably inllruments of tliis 

 kind : it woidd be too much to conclude that every one was 

 eretled for allronomical purpofes, but tliis was probably 

 their original dtllination ; and the figure of an obelilk being 

 rather pleafing to the imagination, it was adojXed as an 

 ornament to public fquares and buildings. As practical 

 allronomy advanced to accuracy and perfeAion, ho\vev«r, 

 the gnomon appeared to be fubjeft to confiderable defects. 

 The ihadow is found to be generally ill defined, fo that its 

 length cannot be very accurately meafured ; and to obviate 

 this, the gnomon muil be of greater height than is eaCly 

 praclicable. In modern Europe, therefore, the original 

 gnomon hat been almoll entirely abandoned, and a new one 

 tubilituted upon principles nearly fimilar, but of a fomc- 

 what different conilruftion. 



The gnomons of modern Italy are ufually conftrufted 

 in very large edifices ; a fmall aperture is made in the upper 

 part ot the building, which permits a luminous circular 

 image of the fun to be formed on the pavement, en which 

 a meridian hue is accurately traced : a plumb line is iufpendcd 

 from the aperture to the lloor, and thus both the height of 

 the aperture, and the diihuice of the folar image frJm the 

 point immediately beneath it, is very accurately afcer- 

 tained. 



There are upon record fome very ancient obfervations 

 made with inltruments of thi.'i kind, particularly of Pythias, 

 who obferved the foldices at Marfcillcs above three centu- 

 ries before the ChriiUan era. Pliny mentions an obelilk 

 erected by Augullus : this obelilk was brought from Eg)-pt, 

 and was faid to have been made by Sefolkris, near a thoufand 

 years before Chrift. It was ufed by Manlius for the func 

 purpo'e for which it was originally dellincd, namely, to 

 meafiire the height of the lun. 



The Chinefc have from the carlieft time been in the con- 

 ftant praftice of making ufc of a gnomon. 



In the year 1278, a gnomon 40 feel high was erefted at 

 Pekin, by the Chinefe emperor Co-eheou King. 



Ulugh Beigh, in the )ea^ H37> obferved the folilices at 

 Samarcand by the (luidow of a gnomon l6j tect high : ^nd 

 finiihu- indruments are even f;ud to have been ufed by the 

 ancient inhabitants of Peru. 



The gnomons to which modern allronomy is the raoft in- 

 debted, are chiefly thofe of France and Italy. 

 . Paul Tofcanelli conftrufted a gnomon in the cathedral of 

 Florence, whofe height was 280 feet. Ximencs repaired 

 this, and publilhcd an account of it in 1757. 



3 D Gaifeadi 



