212 Proceedings of the Royal Physical Society. 
TABLE WL! 
Comparison of the Temperature on particular Days of Ponds 
near Kingston, and of the Thames at that town. (These 
are selected cases, the mass of the author's observations 
being worked up in Table IT.) 
Centre of Pond. | ' 
Margins of Thames. Air in Shade. 
Surface. Bottom. j 
Aft.|Sunr|Diff.| Aft. Sunr Diff. Aft. Sunr Diff. Aft. | Sunr|Diff.|Aft.| Sunr|Diff.|_ 
Se ee ee eS ee ee ee eee _—— _— 
Black Pond, February 4, 1893, |44°5| .. Met 44:5 bee salinck sae e | = “it [44-5 ae me et) oe wt 
a March 28, 29, ,, 52°5| 47°5 | 5:0 |49°5| 47°5 | 2-0 |62°0| 44-0 |18°0|48°5| 46°5 | 2°0 |60°5| 33°0 |27°5 
a April 24, 53) 4600) ae s= |6L°O)) 5. - we 76:0, AP .. |60°5| ... =e: Migliore = 
a June 19, 20, 3, |80°5| 71°7 | 8°8 |71-0| 70-0 | 1-0 |88-0; 69°0 19-0 730! 71°0 | 2°0 |87°0| 60:0 |27°0 
54 September 12; 18925|65:5).... 4 <3 \63:0} os |i bo | ce Wl cc-f ie. (62°08) |e eg0c0) een eee 
e November 10, ,, |48°0] .. oe BORD ae rae ee on por {ete Ol 50°0 
-. December Zw eusepe tl 410 ace Mle AICO ell see lee ell ea 39-0} 
Home Park, August 14, 1893, |81°0} .. ae 72-0} ae .. |90°0) 3 (73°2| 84°0 
Bushey Park, ,, 15, >, |82°0 .. |73°0] | 87-0 | -- |74°0 86-0} 
Queen’s Mere, June 14,15, ,, |70-0| 67°0| 3-0 62-7, 62°5 | 0-2|71-0| 67:0 | 4:0 66-9 81-0 53-0 |28-0 
- May 3, » 602} .. | .. |5¢-0! EEO RM 9 OE eA tes} 70°0| .. | 
Note.—All the ponds, except the Queen’s Mere, were 4 to 5 feet deep, and well 
stocked with submerged aquatic plants, as indicated in the text. The Queen’s Mere was 
7 to 8 feet deep and clear ef weeds, characters that explain its relatively low plane 
of temperature, and the slight marginal heating. 
The lengths of the ponds are as follows :— 
Black Pond, Oxshott, . : : ; : 350 yards. 
Home Park Pond, x : : 5 : 250: _,, 
Bushey Park Pond, : : ‘ : : 200° G; 
Queen's Mere, Wimbledon, : ; : ; 10s; 
By the “surface” of a pond I mean the upper 3 inches in the deep parts. By the 
“margins,” shallows 3 inches deep are implied. The Thames is here assumed to be a 
free-flowing river that exhibits the same temperature throughout its mass. The locks and 
weirs, however, by retarding the current and increasing the depth, tend to elevate the 
plane of temperature, so that the differences between the river and pond temperature, 
indicated in this Table and in Table II., would normally be somewhat greater. The same 
self-recording instrument employed in taking the bottom-temperatures of the Thames 
(Part I., p. 292) was here employed. The afternoon temperatures were taken at the 
“maximum ” hour. 
