Now I must tell you how to draw the shape of the three-cornered board _abc_. Fig. 2 shows how it is done. The side _ac_ should always be just five inches long. The side _bc_ is drawn at right angles to _ac_, which you can do with an ordinary carpenter's square. The length of _bc_ depends on the place for which the dial is made. The following table gives the length of _bc_ for various places in the United States, and, after you have marked out the length of _bc_, it is only necessary to complete the three-cornered piece by drawing the side _ab_ from _a_ to _b_. TABLE SHOWING THE LENGTH OF THE SIDE _bc_. -------------------------- Place. _b c_ Inches. -------------------------- Albany 4-11/16 Baltimore 4-1/16 Boston 4-1/2 Buffalo 4-11/16 Charleston 3-1/4 Chicago 4-1/2 Cincinnati 4-1/16 Cleveland 4-1/2 Denver 4-3/16 Detroit 4-1/2 Indianapolis 4-1/16 Kansas City 3-15/16 Louisville 3-15/16 Milwaukee 3-11/16 New Orleans 2-7/8 New York 4-3/8 Omaha 4-3/8 Philadelphia 4-3/16 Pittsburg 4-3/8 Portland, Me 4-13/16 Richmond 3-15/16 Rochester 4-11/16 San Diego 3-1/4 San Francisco 3-15/16 Savannah 3-1/8 St. Louis 3-15/16 St. Paul 5 Seattle 5-9/16 Washington, D. C. 4-1/16 -------------------------- If you wish to make a dial for a place not given in the table, it will be near enough to use the distance _bc_ as given for the place nearest to you. But in selecting the nearest place from the table, please remember to take that one of the cities mentioned which is nearest to you in a north-and-south direction. It does not matter how far away the place is in an east-and-west direction. So, instead of taking the place that is nearest to you on the map in a straight line, take the place to which you could travel by going principally east or west, and very little north or south. The figure drawn is about the right shape for New York. The board used for the three-cornered piece should be about one-half inch thick. But if you are making a window-sill dial, you may prefer to have it smaller than I have described. You can easily have it half as big by making all the sizes and lines in half-inches where the table calls for inches.