The following is from The Biographical Cyclopedia of Representative Men of Maryland and the District of Columbia (1879):

Martenet, Simon J., City Surveyor of Baltimore was born in that city April 13, 1832. His father, Jonas Martenet, a native of St. Blaise, near Neufchatel, Switzerland, came to this country when scarcely of age, and resided from that time in Baltimore. He died in 1835, leaving his widow, Catherine (Johannes) Martenet, with six sons. Mrs. Martenet was a native of Hesse Cassel, Germany, her father having emigrated to this country with his family and settled in Baltimore in the year 1800. Simon J. was less than four years old at the time of his fathers death, and very early was obliged to exert himself for the maintenance of the family. He was sent to the public schools, finishing his course at the High School, which he entered when just over twelve years of age. After attaining the age of thirteen he supported himself by working out of school hours. He early chose the profession of Surveyor and Civil Engineer, and in March, 1849, began to learn the business practically with Mr. Thomas P. Chiffelle, a graduate of West Point, and City Surveyor of Baltimore for several years. Mr. Chiffelle left Baltimore in 1855, and Mr. Martenet succeeded him in business, in which he has continued to the present time with uninterrupted success. In the same year (1855) he was the Democratic candidate for City Surveyor. Though only twenty-three years of age he was fully competent for the position, having for several years previously done the principal work of the office, but was defeated with his whole ticket by the American party, which was then dominant. During the financial crisis of 1857, when his business had somewhat fallen off in the general depression of that period, to fill up his time he commenced surveys of several counties of the State with the design of making maps of the same, and of finally making and publishing a complete and detailed map of the State of Maryland. He had completed surveys and maps of Cecil, Howard, Kent, Anne Arundel, and Prince Georges counties, and had commenced the work in several others, when the civil war interrupted its further prosecution till 1865. Surveys were then completed and maps made of Carroll and Harford counties, and the remaining counties surveyed for the purposes of the State map only, the entire work having required about 15,000 miles of surveys. The large map and atlas of Maryland which bear his name were published in 1867, and are recognized as the standard representation of the geography of the State. So speedy and so general was this recognition that the following year, by act of the Legislature, copies of the maps were supplied to the public schools throughout the commonwealth. In November, 1867, the first year of the return to power of the Democratic party, Mr. Martenet was elected City Surveyor of Baltimore. He was succeeded in 1869 by Mr. Charles P. Kahler, but was re-elected in 1871, and at the end of each term to the present time, filling this responsible office with great acceptance of the people. In 1871-2 he made an atlas containing very accurate and complete maps in detail of the lands of the Canton Company, which comprised a large part of the eastern section within Baltimore City, and extending several miles into the county, and embracing much of the best manufacturing and water front property in and near the city. This atlas shows the real estate operations of the company from its incorporation for over forty years; and he also, in connection with it, established a complete system of grades on the streets to be projected, covering several square miles of the same territory. The long experience, untiring energy, and ability which Mr. Martenet brings to his work, constitute him as the leading man of the city in his profession. His business is conducted with perfect system; his numerous surveys, maps, and other data, accumulated during the last thirty years, are all recorded and indexed on the plan of a recorders office. He was united in marriage, in August, 1853, with Philena L., daughter of Jacob Fussell, of Baltimore. They have five children living. Jefferson and Simon J., Jr., are also surveyors, and associated with their father in business. Jacob Fussell, the third son, is studying medicine; while William H. and Clarissa F. are still in school. Mr. Martenet is a member of the Society of Friends.