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Frank,

Here is a side by side sight reduction on an index card comparing Martelli and Dreisonstok. I think Lecky was being a bit harsh.

Greg Rudzinski

[NavList] Re: Martelli's Time-Sight Tables
From: Frank Reed
Date: 26 Dec 2012 11:35
Attached are a couple of page images of commentaries on Martelli's tables. Lecky in the 1902 edition of his classic "Wrinkles in Practical Navigation" weighs in, citing them as an example of the delusion of short methods. For anyone unfamiliar with him, Lecky was the ultimate authority of practical navigators at the end of the nineteenth century (if you haven't yet, grab a copy of "Wrinkles", hard copy as well as digital). Willis, writing in 1925, likes them better, calling them "convenient" but says it's a "pity" that they have been "obscured by figment". By the way, Willis has sin^2(t/2) where the analyses by Lars and Bob had (1/2)(1-cos(t)). These are two equivalent expressions for the so-called "haversine". Same thing.

-FER

PS: Thanks to Dave Walden for recommending hathitrust.org for book searches, including searches of the Google Books collection. As Google has lately done its usual thing, allowing a good product to atrophy while pursuing the next "big thing", the search function at Google Books itself has become nearly useless --hathitrust.org is better and accesses an even larger collection of digitized materials.
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Attached File: 121578.willis-on-martelli.png (no thumbnail available)
Attached File: 121578.lecky-on-martelli.png (no thumbnail available)

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