observations on atsmospherical refraction at Port Bozven, &c. 125 
which the Observations by Capt. Parry and myself for the 
Amount of Refraction at Port Bowen were made, renders it 
important that the identical thermometer employed should 
be preserved ; I therefore beg to present it to the Society for 
their acceptance : it was prepared with every possible care 
by Mr. Daniell, for the occasion, and is a spirit thermo- 
meter, having an ivory scale, graduated from 110° degrees 
below zero to 94 0 above, of Fahrenheit : — It has also divisions 
according to Reaumur's scale. 
I avail myself of this opportunity of noticing an omission 
in the Table of Abstracted Intensities, page 125 of Part IV. 
of the Philosophical Transactions, for 1826; in which, the 
means of the times of vibration of the horizontal magnetic 
needle only are given. The actual intensities would exhibit 
the law of variation much better than the times, and as I 
have detected some numerical errors in the Table alluded to, 
it would be better to recompute the whole, and convert the 
times into proportional intensities by squaring the reciprocals 
of the times, and multiplying those squares by 10,000,000,000, 
in order to render the results all integral. It is now however 
too late for such recomputation, and all that remains is to put 
the reader on his guard against the errors alluded to. 
HENRY FOSTER; 
H. M. S. Hecla, Deptford, 
March 15, 1827. 
