VOL. XXIV.] PHILOSOPHICAL TRANSACTIONS. 12Q 



clay-bed on the top of the cliff; as also, that they could not be scattered there 

 by crows, gulls, and other sea-fowl, as well as that some of them are likewise 

 bedded in stone at the bottom of the cliff; and although some few of them 

 may be met with on the top of the cliff, yet it is only where the earth has been 

 broken by the digging of ditches, &c. 



The fossils I have found at this cliff, are the following. 1. Buccinum fossile 

 heterostrophum rostratum laevem maximum Listen referens. 2. Buccinum fos- 

 sile rostratum maximum Listeri referens. 3. Buccinum fossile minus ventri- 

 cosum mucroneobtuso. 4. Buccinum fossile tenue minus ponderosum, striatum 

 et undatum. 5. Buccinum fossile tenue confragosum. 6. Buccinum fossile 

 striis prominulis marginalibus insignitum. 7. Buccino-turben fossile reticula- 

 tum minus. 8. Buccino-turben fossile sulcatum, g. Buccino-turben fossile 

 rostratum. 10. Buccino-turben maximum rostratum fossile spiris intils striis 

 elatis insignitis. 11. Cochlea fossilis maxima umbilicata quinque spirarum. 

 12. Cochlea fossilis umbilicata mucrone obtuso. 13. Nerita parva fossilis. 

 J 4. Turbo fossilis spiris duabus striis eminentibus insignitis. 15. Pecten minor 

 fossilis unica aurita. l6. Auricularia maxima. !/• Pectunculus fossilis fere 

 circinatus striis tenuibus, valvis per ginglymon connexis. 18. Pectunculus fos- 

 silis crassus rostro acuto striis majoribus. IQ. Pectunculus fossilis fasciis trans- 

 versis undatis notatis. 20. Pectunculus vulgaris fossilis. 21. Pectunculus 

 fossilis striis majoribus et elatioribus. 22. Pectunculus maximus fossilis Listeri- 

 anum maximum referens. 23. Pectunculites maximus striis latis. 24. Concha 

 parva fossilis fasciis tranversis insignis. 25. Concha longa fossilis fasciata. 

 26. Conchites laevis maxima. 27. Conchites parva fasciata. 28. Trigonella 

 minor sive vulgatior Anglica Lithoph. Brit. 81 6. 



jin Instrument, for seeing the Sun, Moon, or Stays, pass the Meridian of any 

 Place: useful for setting JVatches in all Parts of the World with the greatest 

 Exactness ; to correct Sun-Dials ; to assist in the Discovery of the Longitudes 

 of Places, &c. By the Rev. Mr. William Derham, F. R. S, N° 29 1, 

 p. 1578. 



Of all the methods for finding the meridian of any place, the most commo- 

 dious for common use is an instrument of Sir Christopher Wren's, or two of 

 Mr. Gray's, or one published in the Appendix of a little book, called The 

 Artificial Clockmaker. ^ 



Sir Chr. Wren's contrivance I am informed is thus : at one end of a ruler 

 erect a sight, through which to see the pole-star, &c. At the other end set 

 up two circles of small wire, one within the other ; the diameter of the inner- 

 most, equal to double the tangent of the distance of the pole-star from the 

 VOL. v, S 



