DOC.

16

FOUNDATIONS

OF

GRAVITATION

485

[4]Einstein

first

predicted

this effect

in

Einstein

1907j (Vol. 2,

Doc. 47),

p.

459,

and

came

back

to

it

in

Einstein 1911h

(Vol. 3,

Doc.

23), §3.

He discussed the

possibility

of

its

measure-

ment in his

contemporary correspondence,

encouraging astronomers

to

pursue

the

matter (see

in particular his correspondence

with

W. H.

Julius

in

the

period August-September 1911,

published

in Vol.

5).

For

a

historical

discussion,

see, e.g.,

Earman and

Glymour

1980b.

[5]In

Einstein 1911h

(Vol.

3,

Doc.

23), p.

908,

Einstein had

given a

value of 0.83 seconds

of

arc.

This value

is

half

of what

was

later

predicted

by

general relativity

(see

Einstein

1915d).

Einstein's

interest

in

the

measurement

of this

effect,

as

well

as

his initiative

in

pointing

out to

his

colleagues

the need for

an

astronomical

test

of his

prediction,

is

documented

by

his

con-

temporary correspondence

(see in

particular

the letters

he

exchanged

with Erwin Freundlich

beginning

in

August 1911, published

in Vol.

5).

Freundlich

may

have attended Einstein's

lecture

(see

Clark

1971,

p.

163).

For

a

historical discussion of the

attempts

at

measuring grav-

itational

light

deflection,

see, e.g.,

Earman and

Glymour

1980a.

[6]For

the

following

line of

argument, see

Einstein and Grossmann

1913

(Doc. 13), part

1,

§§1

and

2,

and Einstein 1913c

(Doc. 17), §5.

[7]See

Grossmann

1913.

[8]This

expression

of the

energy-momentum

conservation

law

corresponds

to

the

equation

derived

in

Einstein 1913c

(Doc.

17),

p.

1257.

Einstein submitted the

manuscript

of Einstein

1913c

(Doc. 17)

on

11 August 1913, a

month before

giving this

lecture

(see

Einstein

to

Alex-

ander

Witting,

11

August

1913

[Vol. 5,

Doc. 464]).

[9]For

the

following,

see

Einstein and Grossmann 1913

(Doc. 13),

part

1,

§5.

[10]Einstein

possibly

refers

to

the so-called "hole

argument,"

first

published

in

Einstein

1914d

(Doc.

26);

see

Stachel

1989, sec. 3;

Norton

1984,

sec. 5;

and

also the editorial

note,

"Einstein

on

Gravitation

and

Relativity:

The Collaboration with Marcel

Grossmann,"

pp.

297-

298,

for

a

historical discussion.

[11]This

argument

is

worked

out in

Einstein 1913c

(Doc. 17),

p.

1258,

and Einstein 1914e

(Doc. 25), p.

178.

[12]The

role of

the

Newtonian

limit

in

determining

Einstein's

field

equations

and

the

problem

of

their

uniqueness are

discussed

in

Norton

1984.

For

the

following equations, see

Einstein

1913c

(Doc. 17), p.

1259; see

also

note

8

for evidence that Einstein submitted the

manuscript

of that

paper

before

delivering

the lecture

on

which the

present paper

is

based.

[13]Einstein discussed the

geometrical implications

of the covariance

properties

of his

field

equations

in

a

letter

to

Ehrenfest

(see

Einstein

to

Paul

Ehrenfest,

before

7

November

1913

[Vol. 5,

Doc.

481]).

[14]See, e.g.,

Mach

1908, chap. 2,

sec.

6,

for Mach's

critique

of fundamental

concepts

of

classical mechanics. For

a

comparative study

of Mach's and Einstein's criticisms of classical

mechanics,

see

Barbour

1992.

[15]See

Einstein 1913c

(Doc. 17), §9,

for

a more

detailed calculation of

this

effect.