While examining Bartholomew Sholto's chamber, Holmes asked Watson to hold the lamp for him so that he could move into the secret room above the chamber. Once inside Watson passed Holmes the lamp so that Watson could join him. (The Sign of Four)

 

The King of Bohemia produced this from under his cloak and placed it on Holmes's table when Holmes asked about expenses. It contained £300 in gold and £700 in notes. (A Scandal in Bohemia)

 

Holmes used his lens to examine the blood-mark on the rope that Jonathan Small used to enter Bartholomew Sholto's chamber. Holmes uses it again to examine the footmarks in the secret room above Bartholomew'c chamber. (The Sign of Four) Also see Magnifying Glass, Double Lens