APPENDIX. 



265 



Mr. John Grant, has suggested the following 

 remedy, which I trust may be found to work 

 well. He has kindly allowed me to introduce it 

 into my little book : 



" Sir, Public attention has for a long time 

 been directed to purifying the water in large ponds 

 and reservoirs ; and, as I have lately succeeded in 

 effecting this desirable object in a fishpond about 

 10 feet deep, the following sketch will enable the 

 public to profit by it. 



" This I have accomplished by simply causing the 

 overflow to proceed from the lower level, or bottom 

 of the pond, instead of from the surface. By this 

 process all the impure and stagnant water is 

 removed, whilst the fresh and surface water is 

 retained a boon to all our public parks. 



" JOHN GRANT." 



" Hyde Park Street, March 30." 



