182 REPORT — 1869. 



of increase, calculated from the observations in August and September, is 

 0°-0187 per foot, or 1° for 53-5 feet. 



This is the bore which was referred to in the following passage of last 

 year's Eeport. 



" It has been selected because the mining engineer states in his report 

 that the coal has been very much burned or charred, showing the effects of 

 heat ; and it becomes an interesting question, Are there any remains of that 

 heat that charred the coal in ancient times, or has it passed off so long ago 

 that the strata are now not sensibly warmer on account of it ? " 



The observations seem to establish the latter alternative, this bore being 

 rather colder than its neighbour, the Blythswood No. 1. 



Mr. Q. J. Symons, Member of the Committee, has furnished the following 

 account of observations taken by him to the depth of 1 100 feet in an artesian 

 boring at Kentish Town : — 



" Observations have been made during a considerable length of time, and 

 with every precaution and care, through the London Clay, Thanet Sands, 

 Chalk, Upper Greeusand, and Gault, in the vicinity of the metropolis, under 

 the following circumstances. 



" There exists in the northern suburbs of London, between Kentish Town 

 and Highgate, a remarkably large well, 8 feet in diameter and 540 feet deep, 

 lined throughout with the finest brickwork, and reaching 214 feet deep into 

 the Chalk. This well was the property of a Company whose Act of Parlia- 

 ment bore date 35th Henry VIII. (a.d. 1544), and afforded a sujjply of 

 water to the surrounding neighbourhood until, in 1852, when, under the 

 joint influence of the Board of Health, who objected to hard water, of in- 

 creasing demand and decreasing quantity, the Company decided on seeking 

 a fresh supply. It was represented to them as most probable that by sink- 

 ing a bore-tube to a depth of about 1000 feet, the Lower Greensand would be 

 tapped, and an abundant supply of excellent water obtained. The then 

 existing well being more than half the entire depth required, it was decided 

 to bore from its bottom, and thus save half the cost. The boring was carried 

 down to 1302 feet (nearly a quarter of a mile), but the Lower Greensand was 

 absent ; some unknown rocks were penetrated, and the Company, after spend- 

 ing on their works, well, and boring nearly £100,000, became bankrupt ; 

 the New River Company purchased the plant, but were advised not to con- 

 tinue the search ; the buildings were sold for old materials, and the whole 

 left in a ruinous condition. 



" I considted other members of this Committee as to the expediency of ob- 

 taining from the New River Comp. permission to experiment on this bore, and 

 consent having (through the courtesy of Mr. Muir, the Company's engineer) 

 been obtained, it was decided that observations should be forthwith commenced. 



" Owing to the ruinous condition of the top of the well, and the depth of 

 the top of the bore-tube below the ground, very considerable danger and 

 discomfort attended the preliminary arrangements, although these very dif- 

 ficulties have eventually led to the detection of sources of error not previously 

 suspected, and to exceptionally accurate results. 



" The accompanying sketches explain pretty clearly the exact circumstances 

 under which the observations were taken, viz. that a hut was erectied over 

 the top of the well to shut out, as far as practicable, external temperature 

 and to protect the apparatus ; that a stout floor was fixed 10 feet down the 

 weU to afford access to the tube * and safety to the observer, the top of the 



* " It is scarcely necessary to say that the tube commences 9 feet below tlie siu-face of the 

 ground, and passes down through the well." 



