Elementary arithmetic, with brief notices of its history... by Robert Potts.

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3. A loaded waggon weighs 2 tons 3cwt. 2qrs. 231b.; the waggon
by itself weighs 18cwt. 3qrs; the load consists of 215 packages, each of
the same weight; find the weight of each.
4. How many packets of 1llb., 131b., 171b., and of each the same
number, may be made out of 3 tons 2cwt. lqr. 231bs.?
5. If one pound of copper be coined into 24 penny pieces, how
many may be coined from a ton of copper, and what is their value?
XXII.
1. By how many grains does an ounce Troy differ from an ounce
Avoirdupois?
2. Reduce 281750 grains Troy to pounds Troy, and find the
equivalent number of pounds Avoirdupois.
3. From one ton Avoirdupois of the lead ore of a certain mine, lib.
lloz. 6dwts. 16grs. Troy of silver is extracted; find how much silver
can be extracted from 17 tons 14cwt. 2qrs. of the same ore.
4. If lib. 8oz. Avoirdupois is half the weight of 31b. 7oz. 15dwts.
Troy, find the number of grains in one pound Avoirdupois.
5. A person purchases goods at the rate of six shillings per pound
Troy weight, and sells them again by Avoirdupois weight; at what
rate must he sell per ounce, so as exactly to reimburse himself?
XXIII.
1. Explain clearly what is meant by an unit of angular measurement. What is the circular measure of an angle, and upon what
geometrical property does this measure depend?
2. The angle subtended at the centre of a circle by a chord equal to
the radius is constant for the same circle. How many French
degrees and how many English degrees are contained in this angle?
3. If 90 English degrees are equal to 100 French degrees, and
one English degree contain 60 minutes and one French degree 100
minutes, give a rule for changing French minutes into English
minutes, and English degrees into French degrees, and conversely.
4. What number of degrees, minutes, &c., in the English scale
corresponds to 30~ 15' 25" in the French scale of angular measure?
5. What is the difference of latitude between St. Peter's at Rome,
41~ 53' 54" N., and St. Paul's in London, 51~ 30' 49" N.?
6. What is the difference of latitude between Greenwich Observatory, which is 51~ 28' 38" North, and that at the Cape of Good Hope,
which is 33~ 36' 3" South?
7. What is the mean of the following observed altitudes of a star,
50~ 17' 35", 50~ 13' 12", 50~ 15' 10", and 50~ 20' 50"?
8. What is the difference of longitude between Athens and Rome,
and between Rome and Philadelphia in the United States; if the
longitude of Athens be 23~ 47' 0" East; the longitude of Rome,
12~ 27' 14"East; and the longitude of Philadelphia, 75~ 10' 0" West,
from Greenwich?