| Funnel-Shaped Cloud of a Tornado | Frontispiece |
| Painted from an unusual Photograph |
| FACING PAGE |
| Exploring the Upper Air—Beginning of a Pilot Balloon Flight | 32 |
| Exploring the Upper Air—Sending Up a Sounding Balloon | 32 |
| Meteorograph for Use with a Sounding Balloon | 33 |
| Kite Meteorograph to be Sent Aloft Attached to a Kite | 33 |
| Alto-cumulus—Fleecy Masses Showing Blue Sky Between | 96 |
| Cumulus, or Wool-pack Cloud | 96 |
| Mammato-cumulus, or “Rain Balls” | 97 |
| Cumulo-nimbus—the Thundercloud | 97 |
| Cloud Banner Over Mount Assiniboine, Canadian Rockies | 100 |
| Cirrus, with Lower Clouds in the Foreground | 100 |
| Lenticular Cloud Over Mount Rainier | 101 |
| Ice Storm at Philadelphia—Trees Covered with Glaze | 116 |
| Nieve Penitente in the Argentine Andes | 117 |
| Clouds or Fog Cascading Through Last Fork CaÑon Into Santa Anita CaÑon | 136 |
| Cloudburst in Southern Utah | 137 |
| Photographic Analysis of Lightning—Single and Double Discharges | 160 |
| Photograph of Lightning, Showing “Black” Flashes | 161 |
| Atmospheric Electricity Instruments | 161 |
| Glass Weather Map in the United States Weather Bureau | 224 |
| The Sun Drawing Water | 225 |
| Orchard Heaters in Operation as Protection Against Expected Frost | 256 |
| Snow Surveyor at Work, Using a Cylindrical Snow Sampler | 257 |
| Snow Rollers, or Wind-blown Snowballs | 257 |
| Bed of the Potomac River Photographed from the Air | 288 |
| Drilling with Compressed Air in a Copper Mine | 289 |
| Launching a Weather Bureau Kite to Explore the Air Over the Ocean | 289 |
| Weather Bureau Kiosk, Union Square, San Francisco | 320 |
| United States Weather Bureau Station at Peoria, Illinois | 320 |
| Central Office of the United States Weather Bureau at Washington | 321 |
