Hand lens of X 10 is found to be suitable for almost every occasion through, the very keen individual may also wish to have a lens of higher magnification. However, higher magnification hand lens may prove to be not very suitable as it will confuse you in the knife marks with the structural characteristics features of timbers.

• HOW TO USE THE HAND LENS

  It is essential to have really Good Light condition showing on the surface of the specimen being examined. The lens should be held as "near to the eye as possible", and the specimen brought up to the lens and position until it is in focus. At first this may prove rather difficult, but with more practice you will soon become quite expert.

  
  

  "Keep both eyes open" when using the lens. This again may require some practice and you will find yourself attempting to close one eye, but it will put much less strain on your eyes if both are kept open when using the lens for any length of time. Take care of your eyes and your lens.