MEASURE OF A DEGREE ON THE COROMANDEL COAST. 313 



may hereafter be referred to, I efeteted small masses of hewn ties marked. 



stone eight feet square at the bottom and four at the top, 



the axis of these masses being made to pass through the 



points of commencement and termination, and in order that 



this might be correctly done, the following method was 



used. 



I marked out the foundation of the building, so that the Structure of 

 ... , . , » iT -ii the truncated 



picket might be as nearly in the centre ot it as possible. pyrami<Jatthe 



The earth was dug about a foot deep, reserving a space end, 

 round the centre untouched. After the foundation was 

 brought to a level with the surface, the first tier of stones 

 was laid, being one foot in height. The inner part was then 

 filled up with stones and mortar, taking particular care at 

 the same time, that the centre was not touched. The next 

 tier of stones was then laid, which was six feet square and 

 one foot high. This also was filled in with great care, and 

 some cement and bricks put gradually round the picket. 

 After that the last tier was laid, which was four feet square, 

 and also one foot high. When these stones were firmly 

 fixed, small silken threads were drawn across each other in 

 the diagonals of the square. A plummet (pointed) was 

 then suspended from the point of intersection of these 

 threads, and they were so moved, that the point of the 

 plummet coincided with the centre of the nail in the picket. 

 The position of these threads being determined, marks were 

 inserted in the stone. The cavity was then filled up, and a 

 square thick stone was fixed in the middle of the mass, hav- 

 ing a circular place of about four inches diameter, sunk half 

 an inch deep, and the centre of which was marked by a point. 

 This point, by moving the stone and again applying the 

 silken threads, was brought to coincide with the point of in- 

 tersection, and then it was firmly fixed and pointed. 



Precisely the same kind of building was erected at the and of that at 

 beginning of the base, but, in place of having a picket in ^J 56 ^™"' 

 the centre, four large hooped ones were driven into the 

 ground, forming a square of about ten feet, the small bam- 

 boo picket being intended as the centre. Silken threads 

 were then drawn across from the diagonal pickets, and so 

 moved, that the plummet first u*ed, suspended from the 

 point of intersection of the threads, might drop into the ca- 

 vity 



