280 Journal oi" the Department of Agriculture. — Sept., 1922. 



Measuring a Tree. 



Achterberp, Cape Province. — Is there an easy method of iiieasur- 

 ing- the heif^lit of a tall tree as it stnnds, and without felling it? The 

 trees that 1 Avant to measure are difficnlt to (dinib, so that it will he 

 very awkward to measure the height by simply climbing up the tree 

 and measuring the height by letting a iape-line hang down the tree. 



iTiootfnntcin ScJiool of Arj)-i,rulture replies: A very easy, and for 

 practical purposes very accurate, method is as follows : Near the tree 

 plant a rod or pole of about 10 feet long vertically in the ground, and 

 measure accurately the height of the pole from the ground surface to 

 the top. Then measure the length of the shadow of the pole and also 

 the length of the shadow of the tree. Multiply the length of the pole 

 by the length of the tree shadow, and divide this product by the length 

 of the jiolc shadow. This will give you the height of the tree. Tlie 

 best time for measuring- will be either in the morning or in the after- 

 noon, when the shadows are longer than the objects which cast the 

 shadows, which will minimize the likelihood of error. 



Field Mice and Skunks. 



Uaijaille, Cape Province. — 1 am tioubled with field mice and 

 skunks in my lucerne lands and sluit walls. Please advise as to 

 the best means for their destructio7i. 



Grootfontein School of Afji-icultvre replies : For the destruction 

 of field mice the following baits can be employed : (a) Ground white 

 arsenic, 1 lb.; cheese, 1 lb.; glycerine, 11 oz. ; water, 3 pints; flour, 

 2| lb. ; aniseed, J lb. Enough black aniline to give a grey colour. 

 Melt the cheese with glycerine in a third of the water; add the flour 

 and the rest of the water. Keep on boiling till the flour is well boiled. 

 Stir in arsenic, aniline, and aniseed. Put pieces as large as a hazel- 

 nut in the passages. 



(6) A bait containing barium carbonate is made as follows : 

 Barium carbonate, 6 oz. ; flour, 10 oz. ; dripping, 4 oz. ; salt, | oz. 

 Use pieces as large as a hazelnut. 



Care should be taken that children or farm animals do not pick 

 up these baits, as poisoning is sure to follow. 



For skunks I would advise putting strychnine in meat and 

 placing it near the burrows. 



Pead Bulletin No. 4, 1921, "The Destruction of Podeuts," 

 obtainable from the Department; price, 3d., j)repaid. 



Basic Slag or Superphosphate. 



Staitdeiton. — -How much basic slag do you recommend me to 

 use per acre for maize? 



Potchefstroovi School of AgricnUure replies : 150-250 lb. is quite 

 sufficient ; but why buy basic slag when you can get a better and a 

 cheaper phosphate in superphosphate? If you are afraid of a sour 

 soil, lime costs only 20s. a ton, and this and super applied separately 

 will give you better returns for less money. 



