Proceedings of the Royal Society. 269 
ticable, on the western part of the N.coast of Spitzbergen. The 
summit was less than two miles from the observatory, in a direction 
nearly due south; the observatory being upon an island rather 
more than a mile from the main land. In consequence of the 
extreme inaccuracy of the plan of Fairhaven, published in Captain 
Phipps’ voyage, the author annexed to this paper a sketch of 
the harbour and adjacent coast, to shew the positions of the hill and 
observatory. The small bay formed by the shore of the main 
land to the north eastward of the hill being frozen over, afforded a 
perfectly level base, and corrections for inequality were thus ren- 
dered unnecessary. A polished copper cone was fixed upon a staff 
at the summit of the hill, the apex of which was proposed as the 
height to the measured; it stood 44 inches above the highest 
pinnacle of the summit. Captain Sabine then entered into the details 
of this trigonometrical measurement, from which the altitude of the 
cone is considered as = 1644 feet. The author next proceeded to 
detail the particulars of the barometrical measurement, and the 
precautions taken to ensure accuracy in the instruments, and in 
their employment; and the height of the cone, thus ascertained, 
was 1640.07 feet. . 
Captain Sabine concluded this paper with some remarks upon 
the incorrectness with which the heights of the hills on this coast 
are set down in Captain Phipps’ voyage. 
An Inquiry into the nature of the luminous power of some of the 
Lampyrides ; namely, the L. Splendidula, L. Italica, and L. Noc- 
tiluca. By T.J.Todd, M.D. Communicated by Sir E. Home, 
Bart. V.P. R.S. 
After adverting to the various opinions entertained respecting 
the luminous powers of these insects and to some of the more usual 
phenomena which attend the emission or production of their 
light, the author proceeded to describe their structure, especially in 
relation to their luminous organs. ‘The peculiar matter in which 
the power of emitting light appears to reside, is adhesive, semi- 
transparent, and granulated. According to Macaire, it is thickly 
penetrated by neryous filaments, and loses its luminous property 
Vou, XVII. U 
