EXAM P LE S.

1. What is the Weight of a Piece of Oak, of a rectangular Form, whofe Solidity is 12096 Cubic Inches?

2. What is the Weight of a Piece of Fir, whofe Girt is 20 Inches, and Length 40 Feet?

3. What is the Weight of an Iron Shot, of 7 Inches Diameter?

4. What is the Weight of an Iron Shot, weighing 42 lb. Avoirdupoife?

5. What is the Weight of an Iron Bomb Shell, of 3 Inches thick, the greatest Diameter being 16 Inches?

6. Required the Weight of one of the Portland Key Stones, to the middle Arch of Westminster-Bridge, the Diameter of the Arch being 76 Feet, the Height of the Key Stone 5 Feet, the Chord of its greatest Breadth, to the Front of the Arch, 3 Feet 4 Inches, and its Depth of the Arch 4 Feet?

7. In the Walls of Balbec, in Turkey, there are three Stones laid End to End, now in Sight, that measure in Length 61 Yards; one of which in particular is 63 Feet long. 12 Feet thick, and Yards over: Now if this Block was Marbie, what Power would balance it, so as to prepare it for moving?

The Weight of any Body being given, to find the Solidity and the specific Gravity thereof.

RULE.

Divide the given Weight by the Tabular Weight corref ponding to the Name of the fame Kind, and the Quotient. will be the Solidity in cubic Inches.

8. What will a Block of Marble, weighing 8 Tons, 14 cwt. come to, at 6s. per Foot folid?

9. Suppose that a Man of War, with all its Ordnance, Rigging, and Appointment, draws fo much Water as to difplace 1300 Tuns of Sea Water, London Beer meafure: The Weight of the Veffel is required?

A a 2

What

10. What will a chain of ftandard Gold weigh in Water that raises a Fluid an Inch, in a Veffel three Inches fquare, when put into it; and fuppofing the Workman had adulterated the said Chain with 14 Ounces of Silver, how much higher would the Water, upon its Immerfion, be raised in the Veffel?

11. Hiero, King of Sicily, ordered his Jeweller to make him a Crown, containing 63 Ounces of Gold; the Workmen thought of fubftituting part Silver therein, to have a proper Perquifite, which taking Air, Archimedes was appointed to examine it, who, on putting it into a Veffel of Water, found it raised the Fluid, or that itself contained 8,2245 Cubic Inches of Metal, and having discovered that the Cubic Inch of Gold more critically weighed 10,36 Ounces, and that of Silver but 5,85 Ounces, he, by Calculation, found what Part of his Majefty's Gold had been changed, and you are defired to repeat the Procefs?

THE

THE

TUTOR'S GUID E.

PART

V.

71.

CHRONOLOGY

S the Art of eftimating and comparing together the Times when any memorable Tranfaction hath happened, fuch as related in History, whether civil or ecclefiaftical.

It also takes a View of the various Facts, Calendars, and Methods of computing Time, practifed by different Nations,. compares them together, and fettles fuch Order and Har. mony among them, that the exact Time in which any remarkable Event happened may be certainly known.

Years Years

of the before World. Chrift..

Some have dated their Events from the

Creation of the World

Others from the Deluge or Flood

The Greeks from their Olympiads of 4

Years each

The Romans from the Building of Rome

The Aftronomers from Nabonaffar King

of Babylon

Some Hiftorians from the Death of Alex

ander the Great

-

We From the Birth of Chrift

A. D.

The Mahomitans from the Flight of Ma- 4626 622

homet, and called the Hegira.

A 3 3

PROBLEM.

To find whether any given Year be Leap Year.

RULE.

Divide the given Year by 4, if o remains, it is Leap Year, but if 1, 2, 3, remains, it is fo many Years after.

EXAMPLE

1. Is 1779 Leap Year?

2. Is 1780 Leap Year?

S.

Note 1.-Every fourth Year is Leap Year, fo called from leaping or advancing a Day more that Year than any other; that Year has then 366 Days in it, and February 29.

To find the Dominical Letter till the Year 1800.

RULE.

To the given Year, add its fourth Part, omitting Fractions, divide that Sum by 7, the Remainder taken from 7, leaves the Index of the Letter in the common Year's Reckoning.

I 2 3 4 5 6 7

A B C D E F G

But in Leap Years, this Letter and its preceding one (in the retrograde Order which thefe Letters take) are the Dominical Letters.

EXAMPLE S.

3. For the Year 1786, I demand the Dominical Letter? 4. For the Year 1788, I demand the Dominical Letter? 2. The Dominical Letter, is that Letter of the Alphabet which points out in the Calendar the Sundays throughout the Year; thence alfo called the Sunday Letter: Of these Letters are confequently seven before mentioned, beginning with the firft Letter of the Alphabet ; and, as in Leap Year there is an intercalary Day, there are then two, one ferving January and February, and its following Letter the remaining Part of the Year.

PROBLEM

To know on what day in the Week any propofed Day of the Month will fall.

RULE.

First find the Dominical Letter, then the Day of the Week the first of the proposed Months fall on, which is known by the two following Lines:

At Dover dwell George Brown, Efquire,

Good Christopher Finch, and David Frier.

Where the firft Letter of each Word answers to the Letter belonging to the first Day of the Months in order, from January to December.

3. You must obferve that the 1ft, 8th, 15th, 22d, and 29th Day of any Month falls on the fame Day of the Week.

5. In 1786, on what Day of the Week does the 19th of May fall, it being Queen Charlotte's Birth-Day? 6. On what Day of the Week does the 4th of June fall in 1788, being King George the Third's Birth-Day?

To find the Year of the Solar, Lunar, or Golden Number, and Indiction Cycles.

RULE.

I

To the given Year add 9 for the Solar, 1 for the Lunar, 3 for the Indiction, divide the Sums in order by 28, 19, and 15, the Remainder in each fhews the Year of its respec tive Cycle.

7. Required the Year of the Solar, Lunar, and Indiction, Cycles, for the Years 1786 and 1788 ?

4. The Solar Cycle, or the Cycle of the Sun, is a Period of 28 Years; in which Time all the Varieties of

the