244 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[July, 



jH'Oceed to mp/ure. k fourth bar of the same size was loaded with 448 tbs., 

 being very nearly its breaking load. It l)ore it for tliutyrseven days, increas- 

 ing its de'tlection dnring the fi.ist few days hy the fractioTi -282 of an inch ; 

 thence retaining the some deflection until it broke. 



The fact thus established, that a beam loaded beyond a certain linut con- 

 tinualh' yields to the load, but with an exceeilingly slow iirogix'ssion, unless 

 the load very nearly approach the breaking load, is one of vast practical im- 

 portance; it ojjeits an entirely new fleld of speculation and inquiry. The 

 questions, what are the limits of loading (if any) beyond whicli this continual 

 progression to rupture beyins .' what are the various rates of progi'ession cor- 

 responding to (/i^l?re«Moads beyond that limit? and what are the elfeets of 

 temperature on these circumstances ? remain, as yet, almost unanswered. 



A series of experiments was directed by Mr. llodgkinson to the verification 

 cf this law, usually assumed in resjiect to the transverse strength of rect- 

 angular licams, that, when their lengths ami brcadtiis are the same, their 

 strengths are as the squares of their dejiths. 



His experiments fully established this law. Thus he placed lietween props, 



4 feet 6 inches apart, castings of Carron iron No. 2., which were all 1 inch 

 broad, and respectively 1, 3, and 5 inches deep; these broke respectively 

 vith weights of 452 ttjs., i$,843 lbs., and 10,050 tbs. ; which arc very nearly 

 as the numbers 1, 9, 25; that is, as the squares of the depths." 



In the original report at page 355, is the result of certain exjierij 

 laents on Carron iron, and the two last in the table are of the greates 

 value, as shewing the importance of tliose in(|uiries to an archi- 

 tect, and the necessity for his obtaining scientific knowledge upon tliis 

 subject in order to a successful and economical application of materials. 

 In tliese tables then it appears that a cast ircjn bar of the T form 

 usually adapted, but with table upwards, thus, T, broke with 2S0 lbs., 

 whilst another bar of the same size and, ccsleris jjaribiis, but with the 

 table downwards, thus, _l, broke with a weight of 980 lbs. 



Another subject, as it appears to me, of great interest, though not 

 exactly in an architectural, but in an arcliaological point of view, is that 

 of the researches lately made on the pyramids of Ghizeh, for Colonel 

 Vyse, by Mr. Perring the engineer, and Mi-. Andrews. 



These wonders of the old world are situated near Cairo, N. w. of the 

 site of the ancient Memphis; and the principal ones are three inmnn- 

 ber. The largest (supposed to have been built by Cheops or Suphis, 

 2100 years before Christ), lias been the main object of these researches. 

 They inform us that the principal part of the stone composing the 

 pyramid has been taken from the rock on which it w as built ; the blocks 

 are roughly scpiared, but built in regular courses, varying from 4 feet 10 

 inches to 2 feet 2 inches in height, in which the breaking of the joints 

 is carefully preserved wherever tliese courses are exposed to sight, 

 as in the platform at the top of the building in the Queen's chamber ; 

 and in the passage leading thereto, and likewise in some other places 

 at the exterior, circular holes are to be observed, about S inclies in 

 diameter and 4 deep, apparently intended to support the macliinery 

 mentioned by Herodotus to have been used for raising the stones from 

 one coiuse to another, and which seem to have been similar to the 

 Polyspaston descrilied by Vitruvius. 



The stone for the revetement, or casing of the exterior, and for the 

 lining of the chambers and passages, is a compact limestone, known to 

 geologists by the name of swinestone or stiukstone, from emitting, 

 when struck, a fetid odour. It was brought from the Gebel Mokattam, 

 on the opposite or Arabian side of the valley of tlie Nile, and the an- 

 cient quarries seem to Ivave been in the neighbourhood of the present 

 village of Tourah. It is of a very compact formation, with but few 

 fossil remains ; the rocks on tlie Lybian side, where tlie pyramids are 

 placed, are, on the contrary, of a loose and granulated texture, abound- 

 ing in marine fossils, and consequently luifit for fine work, and liable to 

 decay. 



The blocks appear to have been finally prepared on tlie level rock 

 in front of the northern face of the pyramid, where several rows 4 or 



5 feet asimder, of 3 or 4 circular holes, about 12 inches diameter, and 

 8 or 10 deep, have been cut, apparently for the purpose of inserting 

 sliears, or for forming a scatfolding for turning or moving the blocks. 



The stone cuttings and rubbish were thrown over the front of the 

 lock in prodigious quantities, where they still remain. 



The mortar used for the casing and lining of the passages was com- 

 posed entirely of lime, but in the body of Uie pyramid it was formed 

 of ground red brick, gravel, Nile earth and crushed granite, or of 

 calcareous stone and lime ; and in some parts, a grout of liquid mortar 

 and desert sand and gravel only has teen used. 



The joints of the casing stones which were discovered at the base 

 of the northern front, those in the king's and queen's chambers, and 

 also in the passages, are so fine as to be scarcely perceptible. 



There has been considerable discussion among the learned respect- 

 ing the term in Herodotus translated by Larcher " revetir et perfeo- 

 tionner:" if the latter word expresses the whole meaning, all diCBculty 

 ceases. Part of the revetement of the central pyramid of the three to 



the eastward of the great j)j-ramid, which remains unfiuislieil, shews 

 the maimer in which this was accomplished. The casing, composed 

 of stones roughly cut to the required angle, was built in horizontal 

 layers corresponding with the courses of the top, till the whole was 

 reduced to one uniform surface. (Beloe.) The ancients always 1^'ft 

 the face of their work to be finished oil' after the building was in other 

 respects com|)leted. 



In pre])aring tlie base of the pyramid, proper care was talcen to 

 ensure the stability of the superstructure, by leveling the rock to a flat 

 bed : and where atlvaiitage was taken of it, to form jiart of the body 

 of the pyramid, it was stepped up in horizontal beds, according to the 

 thickness of the layers of stone used in the building. The general 

 result of these enquiries appears to be the discovery of several cham- 

 bers immediately over the central or king's chamber, the paved 

 platform and the remains of the ancient revetement still existing at the 

 foot of the pyramid, and, contrary to general ijelief, the discovery of 

 the fact that the main passage is so constructed as to allow of the 

 sarcophagus having lieen carried in subsequently to the completion of 

 the pyramid. The upper chambers thus discovered are called by Mr. 

 Perring chambers of construction; they are four in number, of no great 

 height, and appear to have been principally intended to diminish tlie 

 weight of the ceiling of the king's chamber ; they have never been 

 opened before, and on the walls and ceilings are the chalk marks of 

 the workmen, and ruile hieroglyphics coeval with their construction; 

 one of these hieroglyphics in a cartouche appears to read as the name 

 of Suphis. The revetement appears to have been lieautifully wrought, 

 and the mortar so good that the stones have Ijroken when violencelias 

 been used, whilst tlie joint has held soundly. 



The third and last matter I would notice, is the very curious subject 

 of painted arcliitecture and sculpture. It is but few years since the 

 polychromy of the ancient Greeks has forced itself on the attention of 

 the admirers of classic remains ; the dandy amateur puts the subject 

 aside by a sign of horror at tlie idea of painting white marble, and the 

 learned " find it not in their philosophy." Nevertheless, that Greek 

 architecture and statuary were painted, rests on the simple fact that 

 Uiei/ remain so still. 



()ar own ancestors, it is well known, painted the interior of their 

 buildings, as well as their statues, with great and brilliant effect ; and it 

 is now clear that the Greeks did the same. 



The account in a leading periodical seems to sum up our present 

 information on the subject, and to give a sensible reason for this 

 practice. [Given by us at page 220 of the last Journal.] 



To this curious account may be added the still more curious cir- 

 cumstance that even the great pyramids themselves were painted. 

 H. C. Agnew, Esq., who has published very lately a very curious work, 

 makes tlie following statement in " a letter from Alexandria on the 

 evidence of the practical application of the quadration of the circle 

 in the configuration of the second pyramid at Gizeli." In examining 

 the surface I have not been able to detect any coating like that pro- 

 duced by common paint, much less any ilistinct layer of plaster; but 

 the stone seems to have been saturated with some fluid, as oil or var- 

 nish, which has rendered the surface harder as far as it penetrated. 

 Whole acres of this lubricated surface still remain upon the upper 

 part, or casing, as it is called, of the second pyramid." 



In speaking of the great pyramid, Pliny says, "est autem saxo na- 

 turali elaborata et lubricata." The present colour of this outer siu'face 

 is of a brownish yellow, or yellowish brown. It has become darker by 

 time and exposure, like the marble of many antique statues, &c. 



I have thus completed the reference to the subjects I have considered 

 it desirable to notice ; it has been very imperfectly done, bvit it may 

 serve to attract your attention to some matters that are useful and 

 essential, and to give you an interest in othej-s of the most ciuious 

 character. We may not be called upon to build pyramids, nor would 

 our climate permit us to indulge in the gay decorations of the archi- 

 tecture of the Athenians ; but tlie care and thought, and science exhi- 

 bited in the construction of the pyramids ought to be useful to us as 

 examples, and the principles which guided the Greeks in their com- 

 binations of colour, if discovered, miglit lead us to results which would 

 not only justify what appears to us to be a barbarism, but teach us that 

 in this, as in literature, architecture and sculptiue, the Greeks may 

 give lessons to the world. 



A new general chart of the banks of Newfoundland, formed by Captain 

 Davaud and the officers attached to his siurveying expedition in 1837, 1838, 

 and 1839, m which numerous important errors of former charts are rectified, 

 has ju.st been published by order of the Minister of the Marine.— Par/s paper. 



