In order to use a hydrometer properly, it is necessary to observe two precautions:

1. The liquid to be tested should be at exactly the standard temperature (60° F. in the United States, 12.5° C. in Germany, 17.5° 0. in France, 16.5° C. in England) and free from air bubbles. If it is too warm, put the hydrometer jar in a cool place or surround it with water kept at the standard temperature, by means of ice if necessary. If it is too cool bring it into a warm room, and watch a thermometer immersed in the liquid, until it marks the standard temperature; then take its sj)ecific gravity with the hydrometer. Some rough corrections may be made for differences of temperature, but, except to chemists and experts, they are apt to confuse the operator.

2. It is best to fill the hydrometer jar to the top with the liquid, and read across it the degree indicated by the hydrometer. Looking through the glass jar sometimes causes errors in reading.

Table Showing the Relation of the Degrees of Baume's Hy-dbometer to specific gravities, as adopted in the united States.

For Liquids Heavier than Water.

Deg.

Sp.grav.

Deg.

Sp. grav.

Deg.

Sp. grav.

Deg.

Sp. grav.

0

1 0000

19

1 1507

38

1.3551

57

1.6477

1

1.0069

20

1.1600

39

1.3679

58

1 6666

2

1.0139

21

1.1693

40

1.3809

59

1.6860

3

1.0211

22

1.1788

41

1.3942

60

1.7058

4

1.0283

23

1.1885

42

1.4077

61

1.7261

5

1.0357

24

1.1983

43

1.4215

62

1.7469

6

1.0431

25

1.2083

44

1.4356

63

1.7682

7

1.0507

26

1.2184

45

1.4500

64

1.7901

8

1 0583

27

1 2288

46

1.4646

65

1.8125

9

1.0661

28

1.2393

47

1.4795

66

1.8354

10

1.0740

29

1.2500

48

1.4949

67

1.8589

11

1.0820

30

1.2608

49

1.5104

68

1.8831

12

1.0902

31

1.2719

50

1.5263

69

1.9079

13

1.0984

32

1.2831

51

1.5425

70

1.9333

14

1.1068

33

1.2946

52

1.5591

71

1.9595

15

1.1153

34

1.3063

53

1.5760

72

1.9863

16

1.1240

35

1.3181

54

1.5934

73

2.0139

17

1.1328

36

1.3302

55

1.6111

74

2.0422

18

1.1417

37

1.3425

56

1.6292

75

2.0714

For Liquids Lighter than Water.

Deg.

Sp. grav.

Deg.

Sp. grav.

Deg.

Sp. grav.

Deg.

Sp. grav.

10

1.0000

27

0.8917

44

0.8045

61

0.7329

11

0.9929

28

0.8860

45

0.8000

62

0.7290

12

0.9859

29

0.8805

46

0.7954

63

0.7253

13

0.9790

30

0.8750

47

0.7909

64

0.7216

14

0.9722

31

0.8695

48

0.7865

65

0.7179

15

0.9655

32

0.8641

49

0.7821

66

0.7142

16

0.9589

33

0.8588

50

0.7777

67

0.7106

17

0.9523

34

0.8536

51

0.7734

68

0.7070

18

0.9459

35

0.8484

52

0.7692

69

0.7035

19

0.9395

36

0.8433

53

0.7650

70

0.7000

20

0.9333

37

0.8383

54

0.7608

71

0.6965

21

0.9271

38

0.8333

55

0.7567

72

0.6930

22

0.9210

39

0.8284

56

0.7526

73

0.6896

23

0.9150

40

0.8235

57

0.7486

74

0.6863

24

0.9090

41

0.8187

58

0.7446

25

0.9032

42

0.8139

59

0.7407

26

0.8974

43

0.8092

60

0.7368

Table Showing the relation of the Degrees of Baume's, Beck's and Cartier's Hydrometers to Specific Gravity, as Employed in Germany and France.

For Liquids Heavier than Water.

Deg.

Baume 12.5° C.

Beck 12.5° C.

Deg.

Baume 12.5° C.

Beck 12.5° C.

Deg.

Baume 12.5° C.

Beck 12.5° C.

0

1.000

1.000

25

1.205

1.172

51

1.531

1.428

1

1.007

1.006

26

1.215

1.180

52

1.547

1.440

2

1.014

1.012

27

1.225

1.188

53

1.564

1.453

3

1.021

1.018

28

1.235

1.197

54

1.581

1.465

4

1.028

1.024

29

1.246

1.205

55

1.598

1.478

5

1.035

1.030

30

1.256

1.214

56

1.615

1.491

6

1.043

1.036

31

1.267

1.223

57

1.633

1.504

7

1.050

1.043

32

1.278

1.232

58

1.652

1.518

8

1.058

1.049

33

1.289

1.241

59

1.670

1.531

9

1.065

1.056

34

1.301

1.250

60

1.690

1.545

10

1.072

1.062

35

1.312

1.259

61

1.709

1.559

11

1.081

1.069

36

1.324

1.268

62

1.730

1.564

12

1.089

1.076

37

1.336

1.278

63

1.750

1.588

13

1.097

1.082

38

1.348

1.288

64

1.771

1.603

14

1.105

1.089

39

1.361

1.297

65

1.793

1.619

15

1.113

1.096

40

1.374

1.307

66

1.815

1.634

16

1.122

1.104

41

1.387

1.317

67

1.837

1.650

17

1.131

1.111

42

1.400

1.328

68

1.861

1.666

18

1.140

1.118

43

1.413

1.338

69

1.880

1.683

19

1.148

1.125

44

1.427

1.349

70

1.909

1.700

20

1.157

1.133

45

1.441

1.360

71

1.934

1.717

21

1.167

1.141

46

1.455

1.371

72

1.960

1.734

22

1.176

1.148

47

1.470

1.382

73

. . . .

1.752

23

1.185

1.156

48

1.484

1.393

74

. . . .

1.774

24

1.195

1.164

49

1.500

1.405

75

. . . .

1.789

50

1.515

1.416

For Liquids Lighter than Water.

Deg.

Baume 12.5° C.

Beck 12.5° C.

Cartier 17.5° C.

Deg.

Baume 12.5° C.

Beck 12.5° C.

Cartier 12.5° C.

35

0.854

0.829

0.842

70

........

0.708

34

0.859

0.833

0.848

69

........

0.711

33

0.864

0.837

0.853

68

........

0.714

32

0.869

0.841

0.859

67

........

0.717

31

0.874

0.845

0.865

66

.......

0.720

30

0.880

0.850

0.871

65

.......

0.723

29

0.885

0.854

0.877

64

.......

0.726

28

0.890

0.858

0.883

63

.......

0.729

27

0.896

0.863

0.889

62

.......

0.732

26

0.901

0.867

0.895

61

........

0.736

25

0.907

0.872

0.901

60

0.745

0.739

24

0.913

0.876

0.908

59

0.749

0.742

23

0.918

0.880

0.914

58

0.753

0.745

22

0.924

0.885

0.921

57

0.757

0.749

21

0.930

0.890

0.928

56

0.760

0.752

20

0.936

0.894

0.934

55

0.764

0.755

19

0.942

0.899

0.941

54

0.768

0.759

18

0.948

0.904

0.948

53

0.773

0.762

17

0.954

0.909

0.955

52

0.777

0.765

16

0.961

0.914

0.962

51

0.781

0.769

15

0.967

0.919

0.970

50

0.785

0.772

14

0.973

0.924

0.977

49

0.789

0.776

13

0.980

0.929

0.985

48

0.794

0.780

12

0.987

0.934

0.992

47

0.798

0.783

11

0.993

0.939

46

0.802

0.787

10

1.000

0.944

45

0.807

0.790

9

.......

0.949

44

0.811

0.794

8

.......

0.955

43

0.816

0.798

0.800

7

.......

0.960

42

0.820

0.802

0.805

6

.......

0.966

41

0.825

0.806

0.810

5

.......

0.971

40

0.830

0.809

0.815

4

.......

0.977

39

0.834

0.813

0.821

3

.......

0.982

38

0.839

0.817

0.826

2

.......

0.988

37

0.844

0.821

0.831

1

.......

0.994

36

0.849

0.825

0.837

0

.......

1.000

Table Showing the Relation of the Degrees of Twaddel's Hydrometer to Specific Gravity, as Adopted in England.

For Liquids Heavier than Water, Temp. 16.5° C.

Deg.

Sp. grav.

Deg.

Sp . grav.

Deg.

Sp. grav.

Deg.

Sp. grav.

0

1.000

50

1.250

100

1.500

150

1.750

1

1.005

51

1.255

101

1.505

151

1.755

2

1.010

52

1.260

102

1.510

152

1.760

3

1.015

53

1.265

103

1.515

153

1.765

4

1.020

54

1.270

104

1.520

154

1.770

5

1.025

55

1.275

105

1.525

155

1.775

6

1.030

56

1.280

106

1.530

156

1.780

7

1.035

57

1.285

107

1.535

157

1.785

8

1.040

58

1.290

108

1.540

158

1.790

9

1.045

59

1.295

109

1.545

159

1.795

10

1.050

60

1.300

110

1.550

160

1.800

11

1.055

61

1.305

111

1.555

161

1.805

12

1.060

62

1.310

112

1.560

162

1.810

13

1.065

63

1.315

113

1.565

163

1.815

14

1.070

64

1.320

114

1.570

164

1.820

15

1.075

65

1.325

115

1.575

165

1.825

16

1.080

66

1.330

116

1.580

166

1.830

17

1.085

67

1.335

117

1.585

167

1.835

18

1.090

68

1.340

118

1.590

188

1.840

19

1.095

69

1.345

119

1.595

169

1.845

20

1.100

70

1.350

120

1.600

170

1.850

21

1.105

71

1.355

121

1.605

171

1.855

22

1.110

72

1.360

122

1.610

172

1.860

23

1.115

73

1.365

123

1.615

173

1.865

24

1.120

74

1.370

124

1.620

174

1.870

25

1.125

75

1.375

125

1.625

175

1.875

26

1.130

76

1.380

126

1.630

176

1.880

27

1.135

77

1.385

127

1.635

177

1.885

28

1.140

78

1.390

128

1.640

178

1.890

29

1.145

79

1.395

129

1.645

179

1.895

30

1.150

80

1.400

130

1.650

180

1.900

31

1.155

81

1.405

131

1.655

181

1.905

32

1.160

82

1.410

132

1.660

182

1.910

33

1.165

83

1.415

133

1.665

183

1.915

34

1.170

84

1.420

134

1.670

184

1.920

35

1.175

85

1.425

135

1.675

185

1.925

36

1.180

86

1.430

136

1.680

186

1.930

37

1.185

87

1.435

137

1.685

187

1.935

38

1.190

88

1.440

138

1.690

188

1.940

39

1.195

89

1.445

139

1.695

189

1.945

40

1.200

90

1.450

140

1.700

190

1.950

41

1.205

91

1.455

141

1.705

191

1.955

42

1.210

92

1.460

142

1.710

192

1.960

43

1.215

93

1.465

143

1.715

193

1.965

44

1.220

94

1.470

144

1.720

194

1.970

45

1.225

95

1.475

145

1.725

195

1.975

46

1.230

96

1.480

146

1.730

196

1.980

47

1.235

97

1.485

147

1.735

197

1.985

48

1.240

98

1.490

148

1.740

198

1.990

49

1.245

99

1.495

149

1.745

199

1.995

200

2.000