8 DE. A. E. H. TUTTON: 



TJie Foundations. 



The foundations were laid by H.M. Office of Works in a manner which affords the 

 greatest satisfaction. The plan, with two sectional elevations, shown in fig. 5, will 

 render them quite clear. The room which has been set apart for the new comparator 

 is one in the basement of No. 6, Old Palace Yard, the building occupied by the 

 Standards Department of the Board of Trade, which is interesting historically as 

 having been built in 1754 as a residence for the Clerk of the House of Lords, 

 immediately in front of the old Jewel Tower. The latter is also now part of the 

 Standards Office, and is the oldest remaining part of the original Palace of 

 Westminster; it was completed during the reign of Richard IT. Moreover, it is 

 believed that the building of 1754 was erected on the basement of a house of some 

 historic interest, formerly existing on the site, and which was only partly removed to 

 make way for the new building. The new Comparator Room was one of the large 

 wine cellars thus left. 



The room is rather more than 15 feet square and 9 feet high, the ceiling being 

 arched ; the excellently preserved stone walls are upwards of a yard thick. It 

 has one double window and two double doors, eacb provided with two very efficient 

 ventilators. Between each pair of doors and windows, owing to the thickness of 

 the walls, -there is adequate space for the insertion of fans, and for the storage 

 of ice or other means of cooling, if desired on hot summer days when the outside 

 temperature is over G2 F., the official temperature for comparisons. The floor of 

 the room is 10 feet below the street level, and a pit, 11 feet G inches long 

 by 5 feet 6 inches broad, and with a front bay extension of 5 feet 6 inches by 2 feet 



9 inches, was dug out below the floor for a depth of 4 feet down to the virgin soil, a 

 very compact sandy loam. On this foundation concrete blocks were first laid for the 

 support of the cemented brickwork with which the sides of the pit were made secure. 

 Then two separate solid concrete blocks were laid in the midst as indicated in the 

 three drawings (fig. 5), and perhaps most clearly shown in the third, the section CD. 

 An open air space of 6 inches was left all round the blocks, except where the two 

 approach each other, which they each do on one side (the front of the larger block 

 and back of the smaller one) within 2^ inches. 



On the smaller front block of concrete, which reaches- to a height of 6 inches below 

 the floor, and which occupies the front extension of the pit, the smaller block of stone, 

 2 feet by 1 foot 3 inches in basal section and 2 feet 10 inches high, was erected for 

 the support of the interferometer-telescope pedestal. On the larger block of concrete, 

 which rises 1 foot 6 inches above the floor, was laid the larger block of stone, shaped 

 as described in (2) and as shown in the last elevation in fig. 5. The stone is an 

 extremely hard sandstone from Darley Dale, Derbyshire. The floor in the immediate 

 proximity of the blocks, and covering the whole of the pit, is laid in slate slabs 

 supported by rolled-steel joists resting only on the outer brickwork lining the pit ; 



