Schott, who worked for the Coast and Geodetic Survey, appears to have done the analysis of Hayes’ data in 1865. At end of Part I, the “Computation of the Astronomical Observations” is a draft letter from Schott to Hayes (Feb. 13, 1865) about their publication.
Part II is Magnetic Observations (in books labeled V. VI and VII). Schott was doing this on contract with the Smithsonian & on June 3, 1865 sent them a bill for $175—see tipped in letter at end of Vol. VI. An earlier letter from Nov. 28, 1864, outlining payment is tipped in front of Vol. VII.
A later volume, Box 2 of Box 1 of the Schott papers has letter from Schoot to Howgate, April 10, 1880 (re Howgate’s hope of magnetic observations at LFB) in response to Howgate’s request on April 6, 1880: If there is any special magnetic work that occurs to you as being desirable from this locality [LFB] be kind enough to indicate it and I will endeavor to have it done as well as possible. Very Truly Yours H. W. Howgate.
Howgate used a handsome letterhead with a round map of the Arctic regions covering half of the front sheet and naming Lady Franklin Bay. On April 14 he thanked Schott for his of April 10: I hope to see you in person before the Expedition starts and when we can talk this subject over more fully.
The last volume in this box has to do with US rain tables & wind measurements. Schott in 1870 was finding work for a Mr. Diebitsch (re Josephine?). These three volumes are mostly observations and tables, with incoming correspondence laid in and many of Schott’s draft replies included.