Brian Underhill remembers his late father, Robert, as a reserved and solitary man. Robert Underhill had been a philosopher and a celebrated mountaineer in the 1930s, his life spent among his thoughts and the outdoors.

When Brian was born, Robert was 50 years old. What had his father been like as a young man? Brian wondered. He didn’t count on finding out.

But a stash of 1920s love letters recently discovered inside the wall of an old Baltimore home offered a picture of his father’s youth. In dozens of frothy letters, Robert Underhill professed his love for the wife of a Johns Hopkins scientist. Robert poured his fantasies, jealousies and desires onto page after page.

“I’m very surprised to see how he wrote the love letters,” said Brian, 85, of Boulder, Colorado. “I didn’t see anything like that. He just didn’t seem to have the same personality when I knew him.”

As Robert’s only surviving son, Brian was tickled when The Banner called to tell him that his father’s youthful love letters had turned up in the wall of a 1910 house in Roland Park. The letters had been carefully folded in their envelopes, bound with twine and hidden in a little black tin box. When the homeowner, Joanna Meade, was having her bathroom renovated, workers stumbled upon the stash.

The letter writer had simply signed “R.” It has taken some detective work to identify him as Robert Lindley Murray Underhill.

Robert’s 67 letters also have filled in puzzle pieces for the family of his love interest, Edith Spaeth.

She is remembered today as one of America’s first syndicated woman science writers. When Robert was writing to her in 1920, she had been married for seven years to the renowned Johns Hopkins scientist Dr. Reynold Albrecht Spaeth.

Reynold and Robert were roommates at Haverford College, part of the 34-man class of 1909. Robert served as an usher in the 1913 wedding of Reynold and Edith.

Robert wrote to Edith that year, the lone typed letter in the tin box:

… Also please tell me what other fellows in dear old Nineteen-Nine are going to usher, or for that matter are pretty likely to show up, so that I can arrange to get hold of them after the performance.

Reynold died at age 39 of blood poisoning overseas. He had been working to start a medical school in Bangkok and studying the native gibbons. Widowed, Edith returned to Baltimore to raise their two children alone, living for a time in what is now Meade’s home.

Edith gave up journalism and worked as a medical librarian in Washington, D.C. She later moved to California and died in September 1968, at age 80.

“We had little contact with my grandmother Edith and family history was rarely discussed — too much pain and loss. So finding something as simple as Reynold’s graduation photo is a revelation,” emailed Pat Spaeth, 75, of Chicago, Edith’s granddaughter.

Now, both families want to read the love letters in full. They may soon have their chance.

Meade is considering donating the letters to the Maryland State Archives in Annapolis. There, archivists would digitize the letters and make them available online.

As a history enthusiast herself, Meade has found it all a thrill — discovering the letters and unlocking their secrets. Sometimes she thinks about a widowed Edith walking through the rooms of her Roland Park home.

“I hope the house was as comforting to her as it has been to me,” Meade said.