360 



On the Measurement of the Ilahy Guz. 



[July, 



VII. — On the Measurement of the Ilahy Guz, of the Emperor Akber. 



By W. Cracroft, Esq. 

 [In a letter to the Editor.] 

 In the determination of the Ilahy guz, given in your useful tables 

 with the June number of the Journal, I observe that Colonel Hodgson 

 has deduced a length of 33.58 inches from the average measure of the 

 marble slabs of the pavement of the Taj at Agra, and that other lengths 

 which he has deduced from that building, vary from 32.54, to 35.8, a 

 difference of 3.26 inches, or nearly one-tenth of the whole measure. Go- 

 vernment having fixed 33 inches as an arbitrary value of the Ilahy guz, 

 it is no longer an object of importance in point of practice to seek 

 further for its original length ; it may still however be a matter of 

 curiosity, and as that deduced from my own measures of the marble 

 slabs of the Taj, and other parts of the building, (made at the Colonel's 

 request in 1826,) differs from his very much, I send you the detail of 

 my measurement, which you can publish whenever more interesting 

 matter be not at hand. I made use of a surveyor's measuring tape, 

 the error of which I ascertained by marking off lengths of a well 

 executed 2-feet brass scale, by Watkins, on the terrace of a veran- 

 dah, with a fine black-lead pencil, carefully covering the pencil marks at 

 each division by the assistance of a magnifying lens, and obtained the 

 following, taken off with hair compasses and measured on the diagonal 



scale. 



feet. error of tape. ft. error. ft. error. 



At 



56 

 57 



0.93 

 0.95 



58 

 59 



1.00 

 .95 



60 

 65 



n 



1.00 



All my longest measures, from 44 to 49 slabs, being within these 

 numbers of feet, the error has been assumed at one inch in 60 feet, or 

 1.720 part of the whole, and is additive, the tape being too long, and 

 giving the lengths less than they really were. 



Measures on 



the east 



side of the Taj, 





Direction North and South. 





Slabs. 



feet. 



inches. 



1 



45 



60 



2.5 



2 



45 



60 



1.5 



3 



46 



61 



3.5 



4 



44 



58 



7.3 



5 



46 



61 



3.5 





Direction E. and W. 



6 



48 



63 



6.8 



7 



48 



63 



8.2 



8 



48 



63 



8.6 



9 



49 



65 



2.9 

 In other parts o 



19 



46 



61 



6.5 



20 



49 



65 



0.6 



21 



49 



65 



1.4 





South side of the Taj 







Direction East and West. 





Slabs. 



feet. 



inches 



10 



49 



65 



4.8 



11 



49 



64 



1.8 



12 



49 



65 



0,5 



13 



49 



65 



0.2 





Direction N. and S 





14 



45 



60 



1.7 



15 



45 



60 



1.2 



16 



45 



60 



2.0 



17 



45 



60 



3.1 



18 



45 



60 



1.2 



the 



pavements. 







22 



49 



65 



1.5 



23 



49 



65 



2.0 



24 



45 



60 



2.5 



