1848. I 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



141 



ployed in colonial surveying. For instruments used in the busli, 

 portability is of course rather more important than it would be on the 

 Sussex Downs. There are various risks from rough usage to be 

 guarded against or remedied in the former situation which are com- 

 paratively immaterial in the latter; and on allthese points our author 

 gives minute instruction. Chapters 11. and III. detail the methods 

 of layingout town and country lands, and the particular objects which 

 demand the attention of the'explorer are carefully explained. Tlie 

 fourth cha))ter (on practical astronomy) does not from its nature 

 admit much that is new, but appears to be a useful compendium. 

 There are two other chapters, on marine surveying and colonial 

 roads, and some tables of mean refraction, corrections for the sun's 

 declination, &c. On the whole, we are inclined to think that when 

 the English surveyor packs up for the colouies, he ought to put 

 Mr. Whitehead's treatise in a accessible corner of his portmanteau. 



IMPROVED MODE 



OF WORKING EXPANSIVE STEAM 

 VALVES. 



Communicated to the Mining Journal, by Mr. Thomas Cbaddock, 

 of Birmingham. 



Fig. 1 is an end elevation ; and fig. 2 a side elevation. In this 

 design, one eccentric, which is shown at -l, 4, 4, is made to give mo- 

 tion to both the steam and expansive valves. The time at which it is 



Fig. 1. 



Fig. 



desired to open and close the expansive valve, in relation to the stroke 

 of the piston, will lie understood from the following descrijjtion of 

 the pai'ts : — a a is the clip and eccentric rod, which communicates 

 motion from the eccentric 4, 4, 4, to the expansive valve n, through 

 the right angular lever b and rf, which moves upon the pin c, which 

 is attached to the small projecting parts ,v «, which project from 

 the lever //—the lever rfrf, terminating in a forked end, which 

 takes into the gi-oove of the circular ring ee, which ring is moved 

 longitudinally by the action of the eccentric through the aforesaid 

 lever 6 and d ; j is another right-angular lever, which communi- 

 cates motion to the expansive valve «, through the valve-rod n' . 

 The part represented at i i, receives its support from the founda- 

 tion, or other fixed part, to which the main shaft of the engine is 

 attached, and has a projecting socket, on which the lever /; and 

 ring e work — so that these parts have no direct communication 

 with the main shaft. The ring does not revolve, but only partakes 

 of the longitudinal motion imparted from the eccentric, and from 

 thence through the levers / and n', to the expansive valve. The 

 arc of the part marked i i, supports the lever/— it being also gra- 

 duated, indicates the point at which the steam is cutoff; as it 

 will be seen that, by moving the lever/ the whole of the jjarts 

 a a, b, d, h, and « s, are carried round with it to any desired angle in 

 relation to the main crank of the engine, whereby the same thing 

 is effected as if the eccentric 4, 4, 4, itself were moved round, 

 which governs the time of opening and closing the expansive valve. 

 The part marked h h, is attached to the lever/ and serves the 



purpose of steadying the eccentric clip, and also embraces the arc 

 ), so as to keep the lever/firmly attached thereto. At q is seen a 

 small lever, acted upon by a spring, lia\ing at the opposite end a 

 pin, wliich, on passing through the lever/ and arc »', holds the 

 lever/firmly in the desired position; whereas, on pressing the 

 smaller lever with the hand, the lever/is liberated and moveable: 

 3, 3, is the eccentric clip, which is supposed to work the steam 

 valve. 



LLANDAFF CATHEDRAL. 



The History, Present Condition, and Projjosed liestoration of Uandaff 

 Cathedral. \ii Mr. T. H. W'yatt. — (Read at the Royal Institute of Briusii 

 Architects, March 20.) 



Upon the history of the cathedral, I shall not detain you at any great 

 length. The first Mshop is stated to have been Duhritius, wlio died hi 

 522, on an island otf the Caernarvonshire coast, and whose bones were in 

 1120 translated to Llandaff by Bishop Urban, the founder of the present 

 cathedral. 



Urban was consecrated the thirtieth bishop of Llandaff in 1108 ; and ti) 

 him all concede the honour of having tounded the present cathedral. At 

 liis first coming, he found liis bishopric in a very poor and miserable conili- 

 tion, — the cliurch razed almost to the ground ; and complaining thereof to 

 the King and the Pope in 1119, he procured letters and gathered large sums 

 together; he pulled down the old church, which was but 28 feet long, Ij 

 feet broad, and 20 feet high ; and in 1 120, according to Leiand and Godnin, 

 — or in 1129, as stated by Dugdale, — he commenced the fabric dedicated to 

 St. Peter and St. Paul. Bishop Godwin (who wrote in IGOl) desciibes this 

 building as "a very elegant one, 300 feet long, 80 feet broad, and adorned 

 at the west end with two stately towers of great height, and a neat chapel 

 of our Ladye ; a work truly magnificent, and to be remembered with honour 

 liy posterity." Urban died in 1 133, whilst travelling towards Rome. From 

 this period to the beginning of the last century there is no further record of 

 any kind that I can find relating to the cathedral, and here conjecture must 

 commence. 



If Bishop Godwin he correct in supposing the church commenced by 

 Urban to have been completed by him with two towers and a Ladye chapel, 

 and to have been 300 feet long, it must have disappeared between the period 

 of his death (1133), and 118^0 or 1190, which will, 1 think, be conceded as 

 tlie earliest date at which the present Early English structure could have 

 been commenced. The extreme length of the present buihhng is only 2G0 

 feet, and its breadth 76 feet. Of pure Norman work, such as we may be- 

 lieve Urban to have executed in the beginning of the twelfth century, we 

 only have the large arch between the presbytery and Ladye chapel ; the re- 

 maining portion of a window on the south side of the presbytery, so curiously 

 stopped up at a later period ; portions of a Norman string-course, with a 

 fret ornament, running round the walls of the presbytery (being the string- 

 course of the Norman clerestory) ; a variety of Norman fragments walled 

 into the presbytery ; and the two doors at the west end of the north and 

 south aisles, which, though later in their detail and finish than the large 

 arch, may fairly be considered as of Urban's time, particularly if he com- 

 menced at the east end and worked westward toward these doors. 



The size of the chancel arch, and the importance and decoration of the aisle 

 doors, clearly prove that they could have formed no portion of the early and 

 insignificant church knocked about by the Normans, and eventually demo- 

 lished by Urban ; for although the preservation of doorways and chancel 

 arches of Norman churches, rebuilt in the thirteenth and lourteenth cen- 

 turies, is of frequent occurrence, yet in this instance 1 think they must have 

 originated with Urban and not have been removed or perpetuated by him. 



The character and finish of the large arch at the east end of the presbytery, 

 clearly proves that it must have opened into a chancel or Ladye chapel: and 

 thus we may believe Urban so far to have realised Godwin's description as 

 to have completed, " a neat chapel of our Ladye." And the existence of 

 pure Norman work, so far westward as the two aisle doors, may be taken as 

 presumptive evidence that Urban completed " a work truly magnificent, and 

 to be remembered with honour by posterity," even if his western towers 

 were fabulous. Certainly these doorways are of rich and beautiful design, 

 and the general character of all the Norman work remaining is of a pure 

 and good period, corresponding with Urban's prelacy. What befel this 

 Norman church, or how it could have been so completely destroyed in the 

 short period between Urban's death and 1180 or 1190, as to have rendered 

 necessary the almost entire rebuilding of the church in a new and distinct 

 style, remains a mystery. Here are no traces of that gradual and clearly- 

 marked transition from Norman to Early English, which we find so evidently 

 and so instructively displayed at Canterbury, Norwich, Gloucester, St. 

 David's, and Buildwas Abbey. With the single exception of the westera 

 doorway (in which the circular arch is retained, though the detail of the 

 shafts and mouldings are Early English), the new work was commenced free 

 from any taint or prejudice of a past style, and stands forth as pure and 

 beautiful an example of Early English composition and detail as any with 

 which I am acquainted. An able writer in the Ecclesiologist thus speaks 



