i66 D R I N K I N G P O O L S. 7. 



pond gives longer en:ip]oyment ^ and the bu- 

 finefs of pond- making being uncertain and 

 inconflant, travelling workmen can afford to 

 make a large pond at a cheaper rate than a 

 fmall one. 



The curve fuperjicies^ or fuperficial contents 

 Ciixhe^Jides^ of a cone twenty yards in diame- 

 ter at the bafc, and two yards high, is about 

 320 fquare yards. This, in making a pond 

 of thofe dimenfions, is the quantity of coating: 

 for each yard of which near 'j\d. was given 

 in the firft inflancc, and lefs than 7 d, in the 

 laft. Sixpence et^ch fquare yard of furface to be 

 coated, may perhaps be taken as a fair raedium 

 price. 



To afcertain the quantity of coating, mca- 

 fure the exacft circumference or rim of the 

 pit, when finally form.ed and adjuiled for 

 claying : this dimcnfion multiplied by half 

 the length (or depth) of the fide (mcafuring 

 from the brink, down the flope, to the cen- 

 ter) is the quantity of furface to be clayed and 

 coated. The digging would (under this 

 mode of calculation) fall proportionally hea- 

 vier on a large pond ihnn on a fmall one ; but 



this 



