Richardson, Evan Carleton2016-10-202016-10-2019361936b14734576(OCoLC)07874651(OCoLC)ocm07874651https://hdl.handle.net/2144/18395Thesis (M.A.)--Boston University, 1936. This item was digitized by the Internet Archive.en-USBased on investigation of the BU Libraries' staff, this work is free of known copyright restrictionsHome-made and improved apparatus and materials in general science instructionThesis/Dissertation