At

the

top

of

a

hill,

your

mother

parks

the

car.

Everyone

gets

out

and

gazes

at

a

deep

green

valley

below,

and

the

snow-topped

mountains

in

the

distance.

Your

father

looks

at

the

gathering

clouds.

‘We’d

better

get

going.

It

looks

like

a

storm

is

coming.’

‘How

do

you

know?’

you

ask.

‘All

these

questions!’

your

father

says.

‘How

tall

are

the

trees?

How

far

away

is

that

mountain?

How

much

does

that

rock

weigh?

How

fast

are

we

going?

What

time

is

it?

What

direction

is

the

park?

Is

there

a

storm

coming?’

You

laugh.

‘I

guess

we’re

just

curious!’

‘It’s

a

good

thing

we

have

the

technology

these

days

to

help

us

answer

those

questions,’

says

your

mother.

You

lean

back

in

the

seat

and

think.

How

did

people

long

ago

figure

out

the

answer

to

those

questions?

What

kinds

of

instruments

do

people

use

today?

Who

invented

them?

Read

on,

and

find

out!