Encyclopedia Dubuque
"Encyclopedia Dubuque is the online authority for all things Dubuque, written by the people who know the city best.”
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Affiliated with the Local History Network of the State Historical Society of Iowa, and the Iowa Museum Association.
GRADOMETER
GRADOMETER. Determining the grade or decline of a street was made easier by an instrument that cost $1.50 from ADAMS COMPANY (Encyclopedia Dubuque). The gradometer measured grade. If a road rose one foot over one hundred feet the incline would be one percent. One hundred percent would be a rise of one hundred feet over an advance of one hundred feet and would be represented by a line of forty-five degrees from a level line.
The gradometer consisted of a curved glass tube filled with alcohol leaving a small bubble like in a carpenter's level. The tube lay in a nickel casting with graduations marked thirty degrees both ways from the center. The instruments could be attached inside an automobile or to the frame of a bicycle or motorcycle for easy reading. The instrument had to be adjusted while a person was occupying the seat so that the beginning reading would be---0.
The instrument was available for ADAMS-FARWELL AUTOMOBILES.
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Source:
The Motor Way, August 13, 1904, p. 155. Online: http://books.google.com/books?id=LmwfAQAAMAAJ&pg=PA155&lpg=PA155&dq=GRADOMETER+%28AUTOMOBILE%29&source=bl&ots=56_TK0nNWc&sig=mA1xYmB3xcbzJEtSbW0zqvI29CE&hl=en&sa=X&ei=q4usUvHME8iurgHn0YDoBQ&ved=0CH8Q6AEwBw#v=onepage&q=GRADOMETER%20%28AUTOMOBILE%29&f=false