alpha rays
The magnifying glass is only used in the Forgery Detection class on Counterfeit Island.
In the Forgery Detection class, you only have to examine the three signatures to identify which one is fake.
You get it when you pass the Forgery Detection training with the assistant curator.
The scream. it is on the top middle level next to the forgery detection lab.
Examine the painting in the package as you did when you scanned the paintings in Forgery Detection. There is a message written underneath.
Pass the assistant curator's test on painting styles. (see related question)
He is the darker-skinned fellow in the suit, who will test your painting knowledge and give you some training in Forgery detection.
As a new museum employee, you are given a key by the assistant curator when you complete your Forgery Detection training.
A synonym for forgery is counterfeit.
Apply for the job with the assistant curator and when you pass the Forgery Detection class, he will give you a key to the Supply Room.
If you complete the rearranging of the paintings, don't wander off until you have finished the Forgery Detection class, after which you get the Supply Room key.
Once you have taken the Underground Tour, you can apply for the job in the museum. After you pass the Forgery Detection class, you get the key to the Supply Room.