The mariners magazine, or, Sturmy's mathematical and practical arts containing the description and use of the scale of scales, it being a mathematical ruler, that resolves most mathematical conclusions, and likewise the making and use of the crostaff, quadrant, and the quadrat, nocturnals, and other most useful instruments for all artists and navigators : the art of navigation, resolved geometrically, instrumentally, and by calculation, and by that late excellent invention of logarithms, in the three principal kinds of sailing : with new tables of the longitude and latitude of the most eminent places ... : together with a discourse of the practick part of navigation ..., a new way of surveying land ..., the art of gauging all sorts of vessels ..., the art of dialling by a gnomical scale ... : whereunto is annexed, an abridgment of the penalties and forfeitures, by acts of parliaments appointed, relating to the customs and navigation : also a compendium of fortification, both geometrically and instrumentally / by Capt. Samuel Sturmy.

I. HOw to divide the Line of Numbers is thus. You must prepare a Ruler of what length you please, and also a Scale of Equal Parts, divided into 100 or 1000: You must count them. But if you divide the Artifici∣al Tangents and Sines with the Line of Number, you were best to divide the Line into 2000 Parts; so will you have 100 on the Line of Numbers. This Table is taken out of the Lo∣garithms, by rejecting the In∣dex or first Figure. It is best to omit the first Number, by rea∣son they will take up so much room; and begin at 1 or 11, and take the Logarithm-part at 41 for the first 10th or Integer. But if you intend to make 100 on your Line of Numbers, first take 100, which is reckoned 1000, as you see in the fore∣going Table, Parts of the Scale of Equal Parts, for the first 10 or middle of the Scale: Then suppose you were to make the first 2 or 20, take with your Instrument or Com∣pass 301 equal Parts, and lay it from 1 to 2, and the same di∣stance will reach from 10 in the middle to 20. In the like manner do with the rest; for 3 or 30 the equal parts is 477, and for 4 or 40, the Log. parts is 602: So you may easily perceive how to do it, by what is written.

A Table for the Division of the Line of Artificial Numbers.

Num.	Log. parts.	Num.	Log. parts.	Num	Log. parts.	Num.	Log. parts.	Num.	Log. parts.
1	00	21	322	41	612	61	785	81	908
2	30	22	342	42	623	62	792	82	913
3	47	23	361	43	633	63	799	83	919
4	60	24	380	44	643	64	806	84	924
5	69	25	397	45	653	65	812	85	929
6	77	26	414	46	662	66	819	86	934
7	84	27	431	47	672	67	826	87	939
8	90	28	447	48	681	68	832	88	944
9	95	29	462	49	690	69	838	89	949
10	100	30	477	50	698	70	845	90	954
11	41	31	491	51	707	71	851	91	959
12	79	32	505	52	716	72	857	92	963
13	113	33	518	53	724	73	863	93	968
14	146	34	531	54	732	74	869	94	973
15	176	35	544	55	740	75	875	95	977
16	204	36	556	56	748	76	880	96	982
17	230	37	568	57	755	77	886	97	986
18	255	38	579	58	763	78	892	98	991
19	278	39	591	59	770	79	897	99	995
20	301	40	602	60	778	80	903	100	1000