1823.] Mr. Goldingham on the Velocity of Sound, 201 



one another; and turning round bow-wise, sometimes with a 

 head under a less angle. Much of the surf rebounding from one 

 part, does not pass along the others ; and what reaches the head 

 is considerably less than would pass to it, if the pier was built in 

 a straight line. 



But one long main pier to form a Fig. e. 

 harbour of the first kind, is not so 

 complete as two main piers having 

 an entrance between them, as in 

 fig. 6. This certainly may be consi- 

 dered as two harbours facing each 



other, and rejecting the surf, but per- 

 mitting it to pass into the space between them. It has a perfect 

 entrance, as is shown in the first essay ; but the other has not, 

 having an open side to the lee-shore, and its entrance is less 

 disturbed by the surf than the head of the long main pier. 



Article IX. 



Experiments for ascertaining the Velocity of Sound , at Madras in 

 the East Indies. By John Goldingham, Esq. FRS.=^ 



Between the years 1793 and 1796 a considerable number 

 of observations were taken by myself, and under my superinten- 

 dence, at the Observatory at Madras, with the view of ascertain- 

 ing the velocity of sound. Not having the exact distances of 

 the guns from the station when I returned to England, I wrote 

 for further information upon the subject — which I had not 

 obtained when I quitted Europe again. I therefore did not 

 bring these experiments forward at the time ; and having a 

 more elevated station to observe from, by the erection of a new 

 building, and the advantage of corroborating distances, by the 

 trigonometrical survey carrying on under the superintendence 

 of Col. Lambton, I entered upon the course of experiments about 

 to be detailed. The former experiments (those of 1793 and 

 1796) were made with Arnold's chronometers, as were these now 

 given. In examining works obtained from libraries here, since 

 1 closed these experiments, for information relative to the results 

 of like experiments by other observers, I found a letter from 

 Col. Beaufoy, in the Annals of Philosophj/f addressed a few 

 years ago to Dr. Thomson ; and recommending to be done in 

 England, what, in all the essential points, has been performed 

 here, as will appear by the following extract : 



" It has frequently excited my surprise, as well as regret, and 

 in which I am no wise singular, that use has not been made of 



* Abstracted from the Phil. Trans, for 1823, Part I. 



