Arthur or Thorleif Egeberg

Looking for information on Arthur or Thorleif Egeberg. I believe they were twins born September 13 in 1875 in Kristiana. I have pictures taken by Ernst Emil Aubert in Christiana and on the back it is written 14 Maumder gummil [I believe that is correct] and is dated November 1876, I have another one of them together with the photographer Thkeodor Larsens in Tonsberg. They look to be 4 or 5 years old in the last one. I believe their mother might have been Ida Marie Gorboe. Also looking for Frederik Waldemar Gorboe born 1855 in Kristiana. I believe Frederik W. was the brother if Ida Marie. Thank you